Necrotizing fasciitis(NF)is a rapidly progressing,life-threatening soft tissue infection,with upper limb NF posing a particularly serious threat to patient survival and quality of life.Negative pressure wound therapy(...Necrotizing fasciitis(NF)is a rapidly progressing,life-threatening soft tissue infection,with upper limb NF posing a particularly serious threat to patient survival and quality of life.Negative pressure wound therapy(NPWT)has shown considerable advantages in accelerating wound healing and mitigating functional impairment.A retrospective study by Lipatov et al.demonstrated that NPWT significantly reduced the time needed for wound closure preparation while enhancing the success rate of local repair.Despite its benefits,certain limitations highlight the need for further optimization.This paper investigates the potential for personalized dynamic regulation of NPWT,its integration with adjunctive therapies,and the role of multidisciplinary collaboration.Furthermore,it explores the incorporation of advanced technologies such as artificial intelligence,imaging modalities,and biomaterials,presenting novel pathways for the personalized management and global standardization of NF treatment.展开更多
BACKGROUND Diabetic foot ulcers(DFUs)are a significant challenge in diabetic care,and the efficacy of negative pressure wound therapy(NPWT)in treating them remains a subject of continuous investigation.AIM To provide ...BACKGROUND Diabetic foot ulcers(DFUs)are a significant challenge in diabetic care,and the efficacy of negative pressure wound therapy(NPWT)in treating them remains a subject of continuous investigation.AIM To provide a comprehensive meta-analysis of the role of NPWT in the manage-ment of DFUs.METHODS A systematic review was performed based on Preferred Reporting Items for Sys-tematic Reviews and Meta-Analyses guidelines,searching databases like PubMed,Embase,Web of Science,and the Cochrane Library.Randomized clinical trials(RCTs)were included to compare NPWT to other dressings for DFUs.Outcomes measured were wound healing time and rate,granulation tissue formation time,amputation rate,and adverse events.Study quality was evaluated using Coch-rane's risk of bias tool.Analyses utilizedχ2,I2,fixed or random-effects models via Stata v17.RESULTS Of the 1101 identified articles,9 RCTs were selected for meta-analysis.Studies spanned from 2005 to 2020 and originated from countries including the United States,Chile,Pakistan,Italy,India,and Germany.Meta-analysis demonstrated a significant improvement in wound healing rate[risk ratio(RR)=1.46,95%CI:1.22-1.76,P<0.01]and a reduction in amputation rate(RR=0.69,95%CI:0.50-0.96,P=0.006)with NPWT.Furthermore,the time for granulation tissue formation was significantly reduced by an average of 19.54 days.However,the incidence of adverse events did not significantly differ between NPWT and control treatments.CONCLUSION NPWT significantly improves wound healing rates and reduces amputation rates in DFUs.It also hastens the formation of granulation tissue.However,the therapy does not significantly alter the risk of adverse events compared to alternate treatments.展开更多
BACKGROUND Patients with paraplegia are vulnerable to ischial pressure ulcers.Surgical treatments often lead to complications such as seroma and infection,necessitating repeated interventions that increase surgical di...BACKGROUND Patients with paraplegia are vulnerable to ischial pressure ulcers.Surgical treatments often lead to complications such as seroma and infection,necessitating repeated interventions that increase surgical difficulty.This case report aimed to introduce a novel treatment strategy combining negative pressure wound therapy(NPWT)with a fenestrated Penrose drain to manage refractory seroma in patients with a history of ischial pressure ulcers.CASE SUMMARY A 63-year-old woman presented with soft tissue defects on the left ischium and right trochanter.After surgical debridement,an inferior gluteal artery perforator(IGAP)flap was used to reconstruct the left ischium.NPWT was applied at a setting of 75 mmHg on postoperative day 3 owing to the development of seroma,combined with a fenestrated Penrose drain to facilitate effective drainage of serous fluid.A 54-year-old man presented with a 4 cm×2 cm ulcer on the left ischium after previous excision and flap coverage.After thorough debridement,the IGAP flap was elevated,and NPWT with a fenestrated Penrose drain was implemented immediately postoperatively at 75 mmHg to promote drainage.Both patients achieved a stable recovery without complications.CONCLUSION NPWT combined with a fenestrated Penrose drain placement is a promising strategy for addressing refractory seromas in cases of complex pressure ulcers.展开更多
Objective: This study aims to investigate the drainage effect and clinical outcomes of negative pressure chest drainage in patients after two-port thoracoscopic valve surgery, comparing the differences in postoperativ...Objective: This study aims to investigate the drainage effect and clinical outcomes of negative pressure chest drainage in patients after two-port thoracoscopic valve surgery, comparing the differences in postoperative pain, hospital stay, and other factors between the negative pressure group and the control group. Methods: This study is a prospective controlled trial that selected patients undergoing two-port thoracoscopic valve surgery at a certain hospital from January 2019 to December 2024. Patients were randomly assigned to the control group and the negative pressure group using a random number table method. The control group consisted of 30 patients (20 males, 10 females, mean age 42.03 ± 12.89 years), and the negative pressure group consisted of 35 patients (26 males, 9 females, mean age 41.84 ± 11.83 years). The control group received traditional chest drainage, while the negative pressure group received negative pressure chest drainage. Postoperative pain scores, hospital stay, drainage time, number of tube blockages, and incidences of pneumothorax or subcutaneous emphysema were recorded and statistically analyzed. Results: The negative pressure group had a significantly shorter postoperative drainage time compared to the control group (49.09 ± 11.99 hours vs. 79.10 ± 7.32 hours, P < 0.001). The postoperative pain score was lower in the negative pressure group (4.49 ± 1.27 vs. 7.03 ± 0.85, P < 0.001), and the hospital stay was significantly shorter (9.83 ± 1.69 days vs. 14.73 ± 2.32 days, P < 0.001). The incidence of pneumothorax or subcutaneous emphysema was significantly lower in the negative pressure group than in the control group (14.29% vs. 56.67%, P = 0.0003). Conclusion: The application of negative pressure chest drainage in patients after two-port thoracoscopic valve surgery can effectively reduce postoperative pain, shorten hospital stay, and lower the incidence of tube blockage and pneumothorax, demonstrating good clinical outcomes.展开更多
BACKGROUND Negative pressure wound therapy(NPWT)is a potential treatment for diabetic foot ulcers(DFUs),although the mechanisms underlying its effectiveness remain unclear.This study posits that NPWT may improve wound...BACKGROUND Negative pressure wound therapy(NPWT)is a potential treatment for diabetic foot ulcers(DFUs),although the mechanisms underlying its effectiveness remain unclear.This study posits that NPWT may improve wound healing by promoting angiogenesis and activating the nuclear factor erythroid 2-related factor 2(Nrf2)/Kelch-like epichlorohydrin-associated protein 1(Keap1)signaling pathway,which is crucial for the body’s defense against oxidative stress.The hypothesis indicates that enhancing antioxidant defenses through NPWT may positively affect the healing process.There are still limited data on the roles of Nrf2,its downstream signaling molecules,and angiogenesis markers in patients undergoing NPWT.AIM To study the mechanism of NPWT in DFUs.METHODS This study included a total of 40 hospitalized patients with DFUs from Xuzhou Central Hospital,who were divided into Control group(n=21)and NPWT group(n=19).The levels of Nrf2 and Keap1 were analyzed in the granulation tissue 7 days after treatment.The wound condition,erythrocyte sedimentation rate(ESR),procalcitonin(PCT),interleukin 6(IL-6),tumor necrosis factor alpha(TNF-α),vascular endothelial growth factor(VEGF),basic fibroblast growth factor(b-FGF),cluster of differentiation 31(CD31),and levels of oxidative stress[malondialdehyde(MDA),superoxide dismutase(SOD),catalase(CAT),and total antioxidant capacity(T-AOC)]were analyzed before and 7 days after treatment by the Mann-Whitney U test.RESULTS The NPWT group demonstrated significant improvements in wound healing compared to the control group after 7 days of treatment.The levels of ESR,PCT,IL-6,and TNF-αwere significantly reduced in the NPWT group compared to the control group(P<0.05),while the levels of CD31,VEGF,and b-FGF showed significant increases(P<0.05).The NPWT group exhibited notable elevations in the levels of Nrf2 and its downstream targets(SOD,CAT,and T-AOC),accompanied by decreases in the levels of Keap1 and MDA(P<0.05).CONCLUSION NPWT may contribute to the healing of DFUs by potentially reducing levels of oxidative stress.Its effects could possibly be enhanced through the action of Nrf2.展开更多
BACKGROUND Prophylactic loop ileostomy is an effective way to reduce the clinical severity of anastomotic leakage following radical resection of rectal cancer.Incisional surgical site infection(SSI)is a common complic...BACKGROUND Prophylactic loop ileostomy is an effective way to reduce the clinical severity of anastomotic leakage following radical resection of rectal cancer.Incisional surgical site infection(SSI)is a common complication after ileostomy closure.AIM To evaluate the efficacy and safety of the micro-power negative pressure wound technique(MPNPWT)in preventing incisional SSI.METHODS This was a prospective,randomized controlled clinical trial conducted at a single center.A total of 101 consecutive patients who underwent ileostomy closure after rectal cancer surgery with a prophylactic ileostomy were enrolled from January 2019 to December 2021.Patients were randomly allocated into an MPNPWT group and a control group.The MPNPWT group underwent intermittent suturing of the surgical incision with 2-0 Prolene and was covered with a micro-power negative pressure dressing.The surgical outcomes were compared between the MPNPWT(n=50)and control(n=51)groups.Risk factors for incisional SSI were identified using logistic regression.RESULTS There were no differences in baseline characteristics between the MPNPWT(n=50)and control groups(n=51).The incisional SSI rate was significantly higher in the control group than in the MPNPWT group(15.7%vs 2.0%,P=0.031).However,MPNPWT did not affect other surgical outcomes,including intra-abdominal complications,operative time,and blood loss.Postoperative hospital stay length and hospitalization costs did not differ significantly between the two groups(P=0.069 and 0.843,respectively).None of the patients experienced adverse effects of MPNPWT,including skin allergy,dermatitis,and pain.MPNPWT also helped heal the infected incision.Our study indicated that MPNPWT was an independent protective factor[odds ratio(OR)=0.005,P=0.025)]and diabetes was a risk factor(OR=26.575,P=0.029)for incisional SSI.CONCLUSION MPNPWT is an effective and safe way to prevent incisional SSI after loop ileostomy closure.展开更多
BACKGROUND Gustilo III fractures have a high incidence and are difficult to treat.Patients often experience difficulty in wound healing.Negative pressure drainage technology can help shorten wound healing time and has...BACKGROUND Gustilo III fractures have a high incidence and are difficult to treat.Patients often experience difficulty in wound healing.Negative pressure drainage technology can help shorten wound healing time and has positive value in improving patient prognosis.AIM To explore the clinical value of the negative pressure sealing drainage technique in wound healing of Gustilo IIIB and IIIC open fractures.METHODS Eighty patients with Gustilo IIIB and IIIC open fractures with skin and soft tissue injuries who were treated in the Second People’s Hospital of Dalian from March 2019 to December 2021 were selected as the research subjects.They were divided into a study group(n=40,healed with negative pressure closed drainage)and a control group(n=40,healed with conventional dressing changes)according to the variation in the healing they received.The efficacy of the clinical interventions,the variations in the regression indicators(time to wound healing,time to fracture healing,time to hospitalization),and the conversion and healing of bacterial wounds were compared 1-3 mo after the intervention.RESULTS The total effective rate of patients among the study group was 95.00%(38/40),which was notably higher than 75.00%(30/40)among the control group(P<0.05).The wound healing time,fracture healing time,and hospital stay of the patients in the study group was shorter than the control group(P<0.05).After the intervention,the negative bacterial culture at the wound site rate and wound healing rate of the patients among the study group increased compared to the control group(P<0.05).CONCLUSION Negative pressure sealing and drainage technology has a good therapeutic effect on patients with Gustilo IIIB and IIIC open fracture wounds with skin and soft tissue injury.It can notably enhance the wound healing rate and the negative rate of bacteria on the wound surface and help to speed up the recovery process of patients.展开更多
BACKGROUND Necrotizing fasciitis(NF)of the upper extremities is a severe surgical pathology,and the incidence of this disease has been steadily increasing in recent decades.Surgical treatment is accompanied by the for...BACKGROUND Necrotizing fasciitis(NF)of the upper extremities is a severe surgical pathology,and the incidence of this disease has been steadily increasing in recent decades.Surgical treatment is accompanied by the formation of extensive wounds,which can be treated with significant difficulties.In recent years,negative pressure wound therapy(NPWT)has proven to be highly effective.It is also promising for the treatment of NF.AIM To explore the effectiveness of NPWT in the treatment of NF of the upper extremities.METHODS The results of the treatment of 36 patients with NF of the upper extremities in two groups(NPWT group and control group;2022−2023)were retrospectively analyzed.In the NPWT group,the NPWT method(120 mmHg;constant mode)was used after surgical treatment.The number of vacuum-assisted dressings in patients ranged from 1 to 3,depending on the dynamics of the wound process.The duration of fixation of one bandage was up to 2−3 d.In the control group,conventional methods of local wound treatment were used.The following indicators were analyzed:The treatment delay,the prevalence of inflammation,the microbial landscape,the number of debridements,the duration of wound preparation for surgical closure,and the nature of skin plastic surgery.RESULTS Most patients experienced a significant treatment delay[4 d,interquartile range(IQR):2–7 d],which led to the spread of the pathological process to the forearm and shoulder.The most common pathogens were Staphylococcus aureus(14;38.9%)and Streptococcus pyogenes(22;61.1%).The average number of debridements per patient was 5(IQR:3–7),with no difference between groups.The average time to prepare wounds for surgical closure was 11±4 d in the NPWT group and 29±10 d(P=0.00001)in the control group.In the NPWT group,the wounds were more often closed with local tissues(15;83.3%),and in the control group,split-thickness skin grafts were more often used(4;50%).CONCLUSION The predominant isolation of Staphylococcus aureus and/or Streptococcus pyogenes from the lesions allowed us to classify these patients as NF type II.Multiple debridement procedures have become a feature of this disease treatment.The use of NPWT has significantly reduced the time required to prepare wounds for surgical closure.Early closure of wounds allows for more frequent use of local tissue repair,which ensures better results.NPWT is a highly effective way to prepare wounds for early surgical closure in patients with upper extremity NF.展开更多
This report describes a novel technique for improving depressed scars using negative pressure suction-assisted autologous fat grafting.A 35-year-old woman presented with a 20-year history of bilateral central buttock ...This report describes a novel technique for improving depressed scars using negative pressure suction-assisted autologous fat grafting.A 35-year-old woman presented with a 20-year history of bilateral central buttock con-cavities,causing aesthetic concerns.To maximize fat graft survival and enhance tissue volume,we implemented intermittent negative pressure suction on the recipient area for one month preoperatively.The patient expressed satisfaction with the cosmetic outcome,and a three-month follow-up confirmed a significantly improved fat graft survival rate.This minimally invasive,cost-effective,and easily reproducible technique offers a promising clinical strategy for treating depressed scars.展开更多
Objective: This study aims to compare the effects of different drainage tube diameters (22F vs. 26F) combined with negative pressure suction on patients after valve replacement surgery, including postoperative indicat...Objective: This study aims to compare the effects of different drainage tube diameters (22F vs. 26F) combined with negative pressure suction on patients after valve replacement surgery, including postoperative indicators and complications. Methods: A total of 104 patients undergoing valve replacement surgery were included and divided into a 22F group (45 patients) and a 26F group (59 patients). The basic characteristics, postoperative ICU stay duration, drainage duration, postoperative complications, and pain scores were compared between the two groups. All data were analyzed using SPSS statistical software, with p Results: There were no significant differences between the two groups in terms of age, sex, and underlying diseases. The ICU stay duration and drainage duration showed no significant differences (p > 0.05). The total drainage volume in the 22F group was significantly lower than that in the 26F group (225 vs. 380 ml, p = 0.035), and the pain scores on the third postoperative day were also significantly lower in the 22F group (p Conclusion: Compared to the 26F group, patients in the 22F group exhibited less postoperative drainage volume and lower pain scores, suggesting that the 22F drainage tube may have better clinical outcomes after valve replacement surgery.展开更多
Background: The inflammatory phase of acute burns can last for 7 days. Meanwhile, severe burns may exhibit persistent inflammation long after the initial tissue damage. Negative pressure wound therapy(NPWT) is recomme...Background: The inflammatory phase of acute burns can last for 7 days. Meanwhile, severe burns may exhibit persistent inflammation long after the initial tissue damage. Negative pressure wound therapy(NPWT) is recommended to treat various lesions, including burns. This study aimed to compare the number of inflammatory cells on days 3, 14, and 21 in deep dermal burns treated with two different therapies.Methods: This experimental study was conducted at the Prof. Soeparwi Veterinary Hospital, Yogyakarta, from February to September 2022. A total of 36 wounds created in 10-kg Yorkshire pig burn models were subjected to one of the following treatments: 0.9% sodium chloride or NPWT. These wounds were then sampled as paraffin blocks for microscopic inflammatory cell counts by an anatomical pathology specialist. Comparative analyses of lymphocytes, neutrophils, and plasma cells were performed using IBM SPSS version 22 for Windows.Results: A significant difference was found only in neutrophil counts on day 3(5.30 ± 5.41), day 14(42.83 ± 38.58), and day 21(9.80 ± 8.97)(P=0.009), with notable changes from day 3 to day 14(37.53 ± 40.51;P=0.043) and day 14 to day 21(-33.03 ± 42.79;P=0.049). Meanwhile, no significant differences were found in either lymphocytes or plasma cells between days in either treatment group.Conclusion: NPWT effectively reduced neutrophil counts on day 21 of treatment, indicating its beneficial effects in preventing prolonged inflammation during wound healing. This demonstrates its potential as an alternative dressing therapy for deep dermal burn injuries.展开更多
BACKGROUND Postoperative unobstructed drainage is an important measure for avoiding hematoma formation and preventing complications from anterior cervical surgery.AIM To discuss the characteristics and key points of c...BACKGROUND Postoperative unobstructed drainage is an important measure for avoiding hematoma formation and preventing complications from anterior cervical surgery.AIM To discuss the characteristics and key points of clinical management of two types of commonly used negative pressure drainage systems in clinical settings.METHODS Two types of commonly used silica gel negative pressure drainage balls and a type of gastrointestinal decompression apparatus were fully emptied and then injected with different amounts of water and air.Following this,the negative pressure values of the three devices were measured.Meanwhile,we undertook a retrospective analysis of the clinical data of 1328 patients who had been treated with different negative pressure drainage apparatuses during their anterior cervical surgery in our department between January 2007 and January 2018.RESULTS As the amount of injected air or water increased,the negative pressure of the silica gel negative pressure drainage ball decreased rapidly,dropping to zero when 150 mL of water or air was injected.In contrast,the negative pressure of gastrointestinal decompression apparatus decreased slowly,maintaining an ideal value even when 300 mL of water or air was injected.And statistical analysis demonstrated that patients who had been treated with the gastrointestinal decompression apparatus were less likely to develop severe complications than those who had been treated with the silica gel negative pressure drainage ball(P<0.05).CONCLUSION This study showed that the gastrointestinal decompression apparatus has the advantages of large suction capacity,long duration of continuous negative pressure,and good drainage effect,all of which are the favorable factors for the use of this apparatus for negative pressure drainage in anterior cervical surgery.展开更多
Objective： We investigated the effects of intermittent negative pressure on osteogenesis in human bone marrowderived stroma cells （BMSCs） in vitro. Methods： BMSCs were isolated from adult marrow donated by a hip o...Objective： We investigated the effects of intermittent negative pressure on osteogenesis in human bone marrowderived stroma cells （BMSCs） in vitro. Methods： BMSCs were isolated from adult marrow donated by a hip osteoarthritis patient with prosthetic replacement and cultured in vitro. The third passage cells were divided into negative pressure treatment group and control group. The treatment group was induced by negative pressure intermittently （pressure： 50 kPa, 30 min/times, and twice daily）. The control was cultured in conventional condition. The osteogenesis of BMSCs was examined by phase-contrast mi- croscopy, the determination of alkaline phosphatase （ALP） activities, and the immunohistochemistry of collagen type 1. The mRNA expressions of osteoprotegerin （OPG） and osteoprotegerin ligand （OPGL） in BMSCs were analyzed by real-time polymerase chain reaction （PCR）. Results： BMSCs showed a typical appearance of osteoblast after 2 weeks of induction by intermittent negative pressure, the activity of ALP increased significantly, and the expression of collagen type I was positive. In the treatment group, the mRNA expression of OPG increased significantly （P〈0.05） and the mRNA expression of OPGL decreased significantly （P〈0.05） after 2 weeks, compared with the control. Conclusion： Intermittent negative pressure could promote osteogenesis in human BMSCs in vitro.展开更多
Under the optimal condition of copper ions adsorption on yeast,we found some different effects among static adsorption, shaking adsorption and negative pressure cavitation adsorption, and the methods of yeast with dif...Under the optimal condition of copper ions adsorption on yeast,we found some different effects among static adsorption, shaking adsorption and negative pressure cavitation adsorption, and the methods of yeast with different pretreatments also affect adsorption of copper ions. At the same time, the change of intercellular pH before and after adsorption of copper with BCECF was studied. The copper distribution was located by using PhenGreen （dipotassium salt and diacetate）, and the surface of yeast was observed by an atomic force microscope. The results showed that negative pressure cavitation can improve bioadsorption capacity of copper ions on yeast. However, the yeasts＇ pretreatment has a higher effect on bioadsorption. It indicates that heavy metal bioadsorption on yeast has much relation with its cellular molecule basis. With the adsorping, the intercellular pH of yeast increased gradually and changed from acidity to alkalescence. These results may suggest that negative pressure cavitation can compel heavy metals to transfer from the cell surface into inside cell and make the surface of yeast coarse.展开更多
Effects of continuous negative pressure water supply on water consumption, growth and development, as well as physiological mechanism and quality of Capsicum annuum L. were investigated in this paper. Meanwhile, the o...Effects of continuous negative pressure water supply on water consumption, growth and development, as well as physiological mechanism and quality of Capsicum annuum L. were investigated in this paper. Meanwhile, the optimal negative pressure water supply conditions for growth of C. annuum L. were screened out to achieve the goals of water conservation, high yield and high quality, thus providing theoretical foundation for its field production. The pot experiment within the greenhouse was utilized; the continuous negative pressure water supply was adopted; the four treatments, artificial watering（CK）, –5 k Pa（T1）, –10 k Pa（T2）, and –15 k Pa（T3） were set; and the daily water consumption, yield, as well as the biomass, nitrate reductase, root activity, vitamin C, capsaicin, and nutrient uptakes of nitrogen（N）, phosphorus（P） and potassium（K） during various stages of its growth were determined. Compared with CK, when the water supply pressure was controlled at –5 to –15 k Pa in the experiment, the total water consumption of C. annuum L. reduced by 53.42 to 67.75%, the total water consumption intensity reduced by 54.29 to 67.14%, and the water use efficiency increased by 12.66 to 124.67%. The N accumulation in a single strain of C. annuum L. from the color turning stage to the red ripe stage increased by 15.99 to 100.55%, respectively, compared with that of CK; the P accumulation increased by 20.47 to 154.00% relative to that of CK, and the K accumulation increased by 64.92 to 144.9% compared with that of CK. Compared with CK, C. annuum L. yield was remarkably improved by 13.79% at T1, and contents of vitamin C, capsaicin as well as carotenoids at all growth stages were enhanced by 13.42–147.01%, 11.54–71.01%, and 41.1–568.06%, respectively. Nitrate reductase activity, root activity and chlorophyll（a＋b） were markedly increased by 335.78–500%, 79.6–140.68% and 114.95–676.19%, respectively, from immature stage to full ripe stage. Adopting the continuous negative pressure water supply for C. annuum L. has a significant water-saving effect, and the water supply pressure being stable at –5 k Pa contributes to its growth and development, improves yield, enhances root activity, promotes nutrient uptake, and improves its quality, thus achieving the effects of water conservation, high yield, high quality and high efficiency.展开更多
Presented a new coal dust control program that was airtight negative pressure dust-control technology at the transpersite,combining with analysis with the movement of air currents and numerical simulation of gas-solid...Presented a new coal dust control program that was airtight negative pressure dust-control technology at the transpersite,combining with analysis with the movement of air currents and numerical simulation of gas-solid flow at the transpersite,and proved the mechanism of precipitation and proliferation for coal dust-controlt in theory.The technol- ogy has made good economic results at the Heidaigou Clean Plant,not only dust concen- tration control within 10 mg/m^3 to the work site,but also substantial energy savings and cost savings.展开更多
The negative pressure conical fluidized bed is widely used in the pharmaceutical industry.In this study,experiments based on the negative pressure conical fluidized bed are carried out by changing the material mass an...The negative pressure conical fluidized bed is widely used in the pharmaceutical industry.In this study,experiments based on the negative pressure conical fluidized bed are carried out by changing the material mass and particle size.The pressure fluctuation signals are analyzed by the time and the frequency domain methods.A method for absolutely characterizing the degree of the energy concentration at the main frequency is proposed,where the calculation is to divide the original power spectrum by the average signal power.A phenomenon where the gas velocity curve temporarily stops growing is observed when the material mass is light,and the particle size is small.The standard deviation and kurtosis both rapidly change at the minimum fluidization velocity and thus can be used to determine the flow regime,and the variation rule of the kurtosis is independent of both the material mass and particle size.In the initial fluidization stage,the dominant pressure signal comes from the material movement;with the increase in the gas velocity,the power of a 2.5 Hz signal continues to increase.A method of dividing the main frequency by the average cycle frequency can conveniently determine the fluidized state,and a novel concept called stable fluidized zone proposed in this paper can be obtained.Controlling the gas velocity within the stable fluidized zone ensures that the fluidized bed consistently remains in a stable fluidized state.展开更多
BACKGROUND Thermal injuries on free transferred or replanted tissues resulting from loss of sensibility are an infrequent occurrence.They require immediate and appropriate management before they progress to an irrever...BACKGROUND Thermal injuries on free transferred or replanted tissues resulting from loss of sensibility are an infrequent occurrence.They require immediate and appropriate management before they progress to an irreversible condition.Although negative pressure wound therapy(NPWT)can prevent wound progression by increasing microcirculation,the inappropriate application of NPWT on complicationthreatened transferred and replanted tissues can induce an adverse effect.CASE SUMMARY A 48-year-old woman who underwent immediate breast reconstruction with a deep inferior epigastric artery perforator free flap.While applying a heating pad directly to the flap site,she sustained a deep second to third-degree contact burn over 30%of the transferred flap on postoperative 7 d.As the necrotic changes had progressed,we applied an NPWT dressing over the burned area after en-bloc debridement of the transferred tissues on postoperative 21 d.After 4 d of NPWT application,the exposed fatty tissues of the flap changed to dry and browncolored necrotic tissues.Upon further debridement,we noted that the wound gradually reached total necrosis with a collapsed vascular pedicle of deep inferior epigastric artery.CONCLUSION Although NPWT has been shown to be successful for treating various wound types,the significant risk of NPWT application in short-lasting reconstructed flap wounds after thermal injury should be reminded.展开更多
A series of experiments on a solid feed system was performed to investigate the effect of negative pressure gradient on the gas-solid flow pattern and hydrodynamic characteristics.Based on the non-fluidized gas-solid ...A series of experiments on a solid feed system was performed to investigate the effect of negative pressure gradient on the gas-solid flow pattern and hydrodynamic characteristics.Based on the non-fluidized gas-solid two phase flow and particulate mechanics in the standpipe,a method for predicting the pressure of the air passing through the recycle chamber and the pressure drop through the loop seal slit in these systems is also presented.The predicted pressure profile along the negative pressure gradient from the proposed model exhibits a good agreement with the experimental data.The experimental data show that the gas flow in the standpipe is always upward in the negative pressure gradients,while the direction ofthe superficial gas velocity through the recycle chamber of the loop seal does not affect the pressure drop in standpipe.It increases with an increasing negative pressure gradient.展开更多
Cover-bearing-type bucket foundation for offshore wind turbines has been paid more and more attention due to its low cost and great bearing capacity. In order to ensure the cover-bearing mode, the muddy soil inside th...Cover-bearing-type bucket foundation for offshore wind turbines has been paid more and more attention due to its low cost and great bearing capacity. In order to ensure the cover-bearing mode, the muddy soil inside the bucket foundation should be reinforced by some soil consolidation methods, such as negative pressure and electro-osmosis. Firstly, tests were conducted to obtain the reasonable current density. Meanwhile, to improve the electro-osmotic speed and effectiveness, other factors such as intermittent power and layout of electrode, were also studied in the tests. Then, the soil reinforcing tests by negative pressure combined with electro-osmosis were performed for the muddy soil consolidation inside the bucket foundation. The results showed that soil reinforcement by negative pressure was quicker and more obvious during the early phase, and electro-osmotic method can affect more range of soil by rational arrangement of electrodes. Compared with negative pressure, the electro-osmotic method was a continuous and relatively slow process of reinforcement, which was complementary to the negative pressure method. The voltage value of electro-osmosis had little effect on the muddy soil reinforcement inside the bucket foundation, and 1.5 A was chosen as the most reasonable current value for scale model testing in the electro-osmotic method.展开更多
基金Supported by Henan Province Key Research and Development Program,No.231111311000Henan Provincial Science and Technology Research Project,No.232102310411+2 种基金Henan Province Medical Science and Technology Key Project,No.LHGJ20220566 and No.LHGJ20240365Henan Province Medical Education Research Project,No.WJLX2023079Zhengzhou Medical and Health Technology Innovation Guidance Program,No.2024YLZDJH022.
文摘Necrotizing fasciitis(NF)is a rapidly progressing,life-threatening soft tissue infection,with upper limb NF posing a particularly serious threat to patient survival and quality of life.Negative pressure wound therapy(NPWT)has shown considerable advantages in accelerating wound healing and mitigating functional impairment.A retrospective study by Lipatov et al.demonstrated that NPWT significantly reduced the time needed for wound closure preparation while enhancing the success rate of local repair.Despite its benefits,certain limitations highlight the need for further optimization.This paper investigates the potential for personalized dynamic regulation of NPWT,its integration with adjunctive therapies,and the role of multidisciplinary collaboration.Furthermore,it explores the incorporation of advanced technologies such as artificial intelligence,imaging modalities,and biomaterials,presenting novel pathways for the personalized management and global standardization of NF treatment.
基金Supported by the National Natural Science Foundation of China,No.82202454 and No.81873934the Wang Zhengguo Trauma Medicine Fund(Growth Factor Revival Plan)No.SZYZ-TR-09+1 种基金the Shandong Provincial Natural Science Foundation Youth Fund,No.ZR2020QH168the Jinan Science and Technology Plan Project,No.202225065。
文摘BACKGROUND Diabetic foot ulcers(DFUs)are a significant challenge in diabetic care,and the efficacy of negative pressure wound therapy(NPWT)in treating them remains a subject of continuous investigation.AIM To provide a comprehensive meta-analysis of the role of NPWT in the manage-ment of DFUs.METHODS A systematic review was performed based on Preferred Reporting Items for Sys-tematic Reviews and Meta-Analyses guidelines,searching databases like PubMed,Embase,Web of Science,and the Cochrane Library.Randomized clinical trials(RCTs)were included to compare NPWT to other dressings for DFUs.Outcomes measured were wound healing time and rate,granulation tissue formation time,amputation rate,and adverse events.Study quality was evaluated using Coch-rane's risk of bias tool.Analyses utilizedχ2,I2,fixed or random-effects models via Stata v17.RESULTS Of the 1101 identified articles,9 RCTs were selected for meta-analysis.Studies spanned from 2005 to 2020 and originated from countries including the United States,Chile,Pakistan,Italy,India,and Germany.Meta-analysis demonstrated a significant improvement in wound healing rate[risk ratio(RR)=1.46,95%CI:1.22-1.76,P<0.01]and a reduction in amputation rate(RR=0.69,95%CI:0.50-0.96,P=0.006)with NPWT.Furthermore,the time for granulation tissue formation was significantly reduced by an average of 19.54 days.However,the incidence of adverse events did not significantly differ between NPWT and control treatments.CONCLUSION NPWT significantly improves wound healing rates and reduces amputation rates in DFUs.It also hastens the formation of granulation tissue.However,the therapy does not significantly alter the risk of adverse events compared to alternate treatments.
基金Supported by Research fund of Dankook University in 2023,No.R202300627.
文摘BACKGROUND Patients with paraplegia are vulnerable to ischial pressure ulcers.Surgical treatments often lead to complications such as seroma and infection,necessitating repeated interventions that increase surgical difficulty.This case report aimed to introduce a novel treatment strategy combining negative pressure wound therapy(NPWT)with a fenestrated Penrose drain to manage refractory seroma in patients with a history of ischial pressure ulcers.CASE SUMMARY A 63-year-old woman presented with soft tissue defects on the left ischium and right trochanter.After surgical debridement,an inferior gluteal artery perforator(IGAP)flap was used to reconstruct the left ischium.NPWT was applied at a setting of 75 mmHg on postoperative day 3 owing to the development of seroma,combined with a fenestrated Penrose drain to facilitate effective drainage of serous fluid.A 54-year-old man presented with a 4 cm×2 cm ulcer on the left ischium after previous excision and flap coverage.After thorough debridement,the IGAP flap was elevated,and NPWT with a fenestrated Penrose drain was implemented immediately postoperatively at 75 mmHg to promote drainage.Both patients achieved a stable recovery without complications.CONCLUSION NPWT combined with a fenestrated Penrose drain placement is a promising strategy for addressing refractory seromas in cases of complex pressure ulcers.
文摘Objective: This study aims to investigate the drainage effect and clinical outcomes of negative pressure chest drainage in patients after two-port thoracoscopic valve surgery, comparing the differences in postoperative pain, hospital stay, and other factors between the negative pressure group and the control group. Methods: This study is a prospective controlled trial that selected patients undergoing two-port thoracoscopic valve surgery at a certain hospital from January 2019 to December 2024. Patients were randomly assigned to the control group and the negative pressure group using a random number table method. The control group consisted of 30 patients (20 males, 10 females, mean age 42.03 ± 12.89 years), and the negative pressure group consisted of 35 patients (26 males, 9 females, mean age 41.84 ± 11.83 years). The control group received traditional chest drainage, while the negative pressure group received negative pressure chest drainage. Postoperative pain scores, hospital stay, drainage time, number of tube blockages, and incidences of pneumothorax or subcutaneous emphysema were recorded and statistically analyzed. Results: The negative pressure group had a significantly shorter postoperative drainage time compared to the control group (49.09 ± 11.99 hours vs. 79.10 ± 7.32 hours, P < 0.001). The postoperative pain score was lower in the negative pressure group (4.49 ± 1.27 vs. 7.03 ± 0.85, P < 0.001), and the hospital stay was significantly shorter (9.83 ± 1.69 days vs. 14.73 ± 2.32 days, P < 0.001). The incidence of pneumothorax or subcutaneous emphysema was significantly lower in the negative pressure group than in the control group (14.29% vs. 56.67%, P = 0.0003). Conclusion: The application of negative pressure chest drainage in patients after two-port thoracoscopic valve surgery can effectively reduce postoperative pain, shorten hospital stay, and lower the incidence of tube blockage and pneumothorax, demonstrating good clinical outcomes.
文摘BACKGROUND Negative pressure wound therapy(NPWT)is a potential treatment for diabetic foot ulcers(DFUs),although the mechanisms underlying its effectiveness remain unclear.This study posits that NPWT may improve wound healing by promoting angiogenesis and activating the nuclear factor erythroid 2-related factor 2(Nrf2)/Kelch-like epichlorohydrin-associated protein 1(Keap1)signaling pathway,which is crucial for the body’s defense against oxidative stress.The hypothesis indicates that enhancing antioxidant defenses through NPWT may positively affect the healing process.There are still limited data on the roles of Nrf2,its downstream signaling molecules,and angiogenesis markers in patients undergoing NPWT.AIM To study the mechanism of NPWT in DFUs.METHODS This study included a total of 40 hospitalized patients with DFUs from Xuzhou Central Hospital,who were divided into Control group(n=21)and NPWT group(n=19).The levels of Nrf2 and Keap1 were analyzed in the granulation tissue 7 days after treatment.The wound condition,erythrocyte sedimentation rate(ESR),procalcitonin(PCT),interleukin 6(IL-6),tumor necrosis factor alpha(TNF-α),vascular endothelial growth factor(VEGF),basic fibroblast growth factor(b-FGF),cluster of differentiation 31(CD31),and levels of oxidative stress[malondialdehyde(MDA),superoxide dismutase(SOD),catalase(CAT),and total antioxidant capacity(T-AOC)]were analyzed before and 7 days after treatment by the Mann-Whitney U test.RESULTS The NPWT group demonstrated significant improvements in wound healing compared to the control group after 7 days of treatment.The levels of ESR,PCT,IL-6,and TNF-αwere significantly reduced in the NPWT group compared to the control group(P<0.05),while the levels of CD31,VEGF,and b-FGF showed significant increases(P<0.05).The NPWT group exhibited notable elevations in the levels of Nrf2 and its downstream targets(SOD,CAT,and T-AOC),accompanied by decreases in the levels of Keap1 and MDA(P<0.05).CONCLUSION NPWT may contribute to the healing of DFUs by potentially reducing levels of oxidative stress.Its effects could possibly be enhanced through the action of Nrf2.
基金Supported by the Zhejiang Provincial Natural Science Foundation of China,No.LQ20H260002.
文摘BACKGROUND Prophylactic loop ileostomy is an effective way to reduce the clinical severity of anastomotic leakage following radical resection of rectal cancer.Incisional surgical site infection(SSI)is a common complication after ileostomy closure.AIM To evaluate the efficacy and safety of the micro-power negative pressure wound technique(MPNPWT)in preventing incisional SSI.METHODS This was a prospective,randomized controlled clinical trial conducted at a single center.A total of 101 consecutive patients who underwent ileostomy closure after rectal cancer surgery with a prophylactic ileostomy were enrolled from January 2019 to December 2021.Patients were randomly allocated into an MPNPWT group and a control group.The MPNPWT group underwent intermittent suturing of the surgical incision with 2-0 Prolene and was covered with a micro-power negative pressure dressing.The surgical outcomes were compared between the MPNPWT(n=50)and control(n=51)groups.Risk factors for incisional SSI were identified using logistic regression.RESULTS There were no differences in baseline characteristics between the MPNPWT(n=50)and control groups(n=51).The incisional SSI rate was significantly higher in the control group than in the MPNPWT group(15.7%vs 2.0%,P=0.031).However,MPNPWT did not affect other surgical outcomes,including intra-abdominal complications,operative time,and blood loss.Postoperative hospital stay length and hospitalization costs did not differ significantly between the two groups(P=0.069 and 0.843,respectively).None of the patients experienced adverse effects of MPNPWT,including skin allergy,dermatitis,and pain.MPNPWT also helped heal the infected incision.Our study indicated that MPNPWT was an independent protective factor[odds ratio(OR)=0.005,P=0.025)]and diabetes was a risk factor(OR=26.575,P=0.029)for incisional SSI.CONCLUSION MPNPWT is an effective and safe way to prevent incisional SSI after loop ileostomy closure.
基金the Review Committee of Fuzhou Medical College of Nanchang University(Approval No.4445644).
文摘BACKGROUND Gustilo III fractures have a high incidence and are difficult to treat.Patients often experience difficulty in wound healing.Negative pressure drainage technology can help shorten wound healing time and has positive value in improving patient prognosis.AIM To explore the clinical value of the negative pressure sealing drainage technique in wound healing of Gustilo IIIB and IIIC open fractures.METHODS Eighty patients with Gustilo IIIB and IIIC open fractures with skin and soft tissue injuries who were treated in the Second People’s Hospital of Dalian from March 2019 to December 2021 were selected as the research subjects.They were divided into a study group(n=40,healed with negative pressure closed drainage)and a control group(n=40,healed with conventional dressing changes)according to the variation in the healing they received.The efficacy of the clinical interventions,the variations in the regression indicators(time to wound healing,time to fracture healing,time to hospitalization),and the conversion and healing of bacterial wounds were compared 1-3 mo after the intervention.RESULTS The total effective rate of patients among the study group was 95.00%(38/40),which was notably higher than 75.00%(30/40)among the control group(P<0.05).The wound healing time,fracture healing time,and hospital stay of the patients in the study group was shorter than the control group(P<0.05).After the intervention,the negative bacterial culture at the wound site rate and wound healing rate of the patients among the study group increased compared to the control group(P<0.05).CONCLUSION Negative pressure sealing and drainage technology has a good therapeutic effect on patients with Gustilo IIIB and IIIC open fracture wounds with skin and soft tissue injury.It can notably enhance the wound healing rate and the negative rate of bacteria on the wound surface and help to speed up the recovery process of patients.
文摘BACKGROUND Necrotizing fasciitis(NF)of the upper extremities is a severe surgical pathology,and the incidence of this disease has been steadily increasing in recent decades.Surgical treatment is accompanied by the formation of extensive wounds,which can be treated with significant difficulties.In recent years,negative pressure wound therapy(NPWT)has proven to be highly effective.It is also promising for the treatment of NF.AIM To explore the effectiveness of NPWT in the treatment of NF of the upper extremities.METHODS The results of the treatment of 36 patients with NF of the upper extremities in two groups(NPWT group and control group;2022−2023)were retrospectively analyzed.In the NPWT group,the NPWT method(120 mmHg;constant mode)was used after surgical treatment.The number of vacuum-assisted dressings in patients ranged from 1 to 3,depending on the dynamics of the wound process.The duration of fixation of one bandage was up to 2−3 d.In the control group,conventional methods of local wound treatment were used.The following indicators were analyzed:The treatment delay,the prevalence of inflammation,the microbial landscape,the number of debridements,the duration of wound preparation for surgical closure,and the nature of skin plastic surgery.RESULTS Most patients experienced a significant treatment delay[4 d,interquartile range(IQR):2–7 d],which led to the spread of the pathological process to the forearm and shoulder.The most common pathogens were Staphylococcus aureus(14;38.9%)and Streptococcus pyogenes(22;61.1%).The average number of debridements per patient was 5(IQR:3–7),with no difference between groups.The average time to prepare wounds for surgical closure was 11±4 d in the NPWT group and 29±10 d(P=0.00001)in the control group.In the NPWT group,the wounds were more often closed with local tissues(15;83.3%),and in the control group,split-thickness skin grafts were more often used(4;50%).CONCLUSION The predominant isolation of Staphylococcus aureus and/or Streptococcus pyogenes from the lesions allowed us to classify these patients as NF type II.Multiple debridement procedures have become a feature of this disease treatment.The use of NPWT has significantly reduced the time required to prepare wounds for surgical closure.Early closure of wounds allows for more frequent use of local tissue repair,which ensures better results.NPWT is a highly effective way to prepare wounds for early surgical closure in patients with upper extremity NF.
基金supported by the Clinical Research Program of Shanghai Ninth People’s Hospital,Shanghai Jiao Tong University School of Medicine(grant no.JYLJ202103)Two-Hundred Talent(grant no.20191916)Shanghai Clinical Research Center of Plastic and Reconstructive Surgery supported by Science and Technology Commission of Shanghai Municipality(grant no.22MC1940300)。
文摘This report describes a novel technique for improving depressed scars using negative pressure suction-assisted autologous fat grafting.A 35-year-old woman presented with a 20-year history of bilateral central buttock con-cavities,causing aesthetic concerns.To maximize fat graft survival and enhance tissue volume,we implemented intermittent negative pressure suction on the recipient area for one month preoperatively.The patient expressed satisfaction with the cosmetic outcome,and a three-month follow-up confirmed a significantly improved fat graft survival rate.This minimally invasive,cost-effective,and easily reproducible technique offers a promising clinical strategy for treating depressed scars.
文摘Objective: This study aims to compare the effects of different drainage tube diameters (22F vs. 26F) combined with negative pressure suction on patients after valve replacement surgery, including postoperative indicators and complications. Methods: A total of 104 patients undergoing valve replacement surgery were included and divided into a 22F group (45 patients) and a 26F group (59 patients). The basic characteristics, postoperative ICU stay duration, drainage duration, postoperative complications, and pain scores were compared between the two groups. All data were analyzed using SPSS statistical software, with p Results: There were no significant differences between the two groups in terms of age, sex, and underlying diseases. The ICU stay duration and drainage duration showed no significant differences (p > 0.05). The total drainage volume in the 22F group was significantly lower than that in the 26F group (225 vs. 380 ml, p = 0.035), and the pain scores on the third postoperative day were also significantly lower in the 22F group (p Conclusion: Compared to the 26F group, patients in the 22F group exhibited less postoperative drainage volume and lower pain scores, suggesting that the 22F drainage tube may have better clinical outcomes after valve replacement surgery.
基金supported by the Community Fund Grant from the Faculty of Medicine,Public Health,and Nursing,Universitas Gadjah Mada,under the 2022 Scheme for Faculty-Postgraduate Medical Education Students(grant no.371/UN1/FKKMK/PPKE/PT/2022).
文摘Background: The inflammatory phase of acute burns can last for 7 days. Meanwhile, severe burns may exhibit persistent inflammation long after the initial tissue damage. Negative pressure wound therapy(NPWT) is recommended to treat various lesions, including burns. This study aimed to compare the number of inflammatory cells on days 3, 14, and 21 in deep dermal burns treated with two different therapies.Methods: This experimental study was conducted at the Prof. Soeparwi Veterinary Hospital, Yogyakarta, from February to September 2022. A total of 36 wounds created in 10-kg Yorkshire pig burn models were subjected to one of the following treatments: 0.9% sodium chloride or NPWT. These wounds were then sampled as paraffin blocks for microscopic inflammatory cell counts by an anatomical pathology specialist. Comparative analyses of lymphocytes, neutrophils, and plasma cells were performed using IBM SPSS version 22 for Windows.Results: A significant difference was found only in neutrophil counts on day 3(5.30 ± 5.41), day 14(42.83 ± 38.58), and day 21(9.80 ± 8.97)(P=0.009), with notable changes from day 3 to day 14(37.53 ± 40.51;P=0.043) and day 14 to day 21(-33.03 ± 42.79;P=0.049). Meanwhile, no significant differences were found in either lymphocytes or plasma cells between days in either treatment group.Conclusion: NPWT effectively reduced neutrophil counts on day 21 of treatment, indicating its beneficial effects in preventing prolonged inflammation during wound healing. This demonstrates its potential as an alternative dressing therapy for deep dermal burn injuries.
基金Supported by the Multicenter Clinical Trial of hUC-MSCs in the Treatment of Late Chronic Spinal Cord Injury,No.2017YFA0105404the Key Discipline Construction Project of Pudong Health Bureau of Shanghai,No.PWZxk2017-08.
文摘BACKGROUND Postoperative unobstructed drainage is an important measure for avoiding hematoma formation and preventing complications from anterior cervical surgery.AIM To discuss the characteristics and key points of clinical management of two types of commonly used negative pressure drainage systems in clinical settings.METHODS Two types of commonly used silica gel negative pressure drainage balls and a type of gastrointestinal decompression apparatus were fully emptied and then injected with different amounts of water and air.Following this,the negative pressure values of the three devices were measured.Meanwhile,we undertook a retrospective analysis of the clinical data of 1328 patients who had been treated with different negative pressure drainage apparatuses during their anterior cervical surgery in our department between January 2007 and January 2018.RESULTS As the amount of injected air or water increased,the negative pressure of the silica gel negative pressure drainage ball decreased rapidly,dropping to zero when 150 mL of water or air was injected.In contrast,the negative pressure of gastrointestinal decompression apparatus decreased slowly,maintaining an ideal value even when 300 mL of water or air was injected.And statistical analysis demonstrated that patients who had been treated with the gastrointestinal decompression apparatus were less likely to develop severe complications than those who had been treated with the silica gel negative pressure drainage ball(P<0.05).CONCLUSION This study showed that the gastrointestinal decompression apparatus has the advantages of large suction capacity,long duration of continuous negative pressure,and good drainage effect,all of which are the favorable factors for the use of this apparatus for negative pressure drainage in anterior cervical surgery.
基金Project (No. 20070421123) supported by the Postdoctoral Science Foundation of China
文摘Objective： We investigated the effects of intermittent negative pressure on osteogenesis in human bone marrowderived stroma cells （BMSCs） in vitro. Methods： BMSCs were isolated from adult marrow donated by a hip osteoarthritis patient with prosthetic replacement and cultured in vitro. The third passage cells were divided into negative pressure treatment group and control group. The treatment group was induced by negative pressure intermittently （pressure： 50 kPa, 30 min/times, and twice daily）. The control was cultured in conventional condition. The osteogenesis of BMSCs was examined by phase-contrast mi- croscopy, the determination of alkaline phosphatase （ALP） activities, and the immunohistochemistry of collagen type 1. The mRNA expressions of osteoprotegerin （OPG） and osteoprotegerin ligand （OPGL） in BMSCs were analyzed by real-time polymerase chain reaction （PCR）. Results： BMSCs showed a typical appearance of osteoblast after 2 weeks of induction by intermittent negative pressure, the activity of ALP increased significantly, and the expression of collagen type I was positive. In the treatment group, the mRNA expression of OPG increased significantly （P〈0.05） and the mRNA expression of OPGL decreased significantly （P〈0.05） after 2 weeks, compared with the control. Conclusion： Intermittent negative pressure could promote osteogenesis in human BMSCs in vitro.
基金The National Basic Research Program (973) of China (No. 2004CB418505)
文摘Under the optimal condition of copper ions adsorption on yeast,we found some different effects among static adsorption, shaking adsorption and negative pressure cavitation adsorption, and the methods of yeast with different pretreatments also affect adsorption of copper ions. At the same time, the change of intercellular pH before and after adsorption of copper with BCECF was studied. The copper distribution was located by using PhenGreen （dipotassium salt and diacetate）, and the surface of yeast was observed by an atomic force microscope. The results showed that negative pressure cavitation can improve bioadsorption capacity of copper ions on yeast. However, the yeasts＇ pretreatment has a higher effect on bioadsorption. It indicates that heavy metal bioadsorption on yeast has much relation with its cellular molecule basis. With the adsorping, the intercellular pH of yeast increased gradually and changed from acidity to alkalescence. These results may suggest that negative pressure cavitation can compel heavy metals to transfer from the cell surface into inside cell and make the surface of yeast coarse.
基金supported by the National High-Technology Research and Development Program of China (863 Program, 2013AA102900-3)
文摘Effects of continuous negative pressure water supply on water consumption, growth and development, as well as physiological mechanism and quality of Capsicum annuum L. were investigated in this paper. Meanwhile, the optimal negative pressure water supply conditions for growth of C. annuum L. were screened out to achieve the goals of water conservation, high yield and high quality, thus providing theoretical foundation for its field production. The pot experiment within the greenhouse was utilized; the continuous negative pressure water supply was adopted; the four treatments, artificial watering（CK）, –5 k Pa（T1）, –10 k Pa（T2）, and –15 k Pa（T3） were set; and the daily water consumption, yield, as well as the biomass, nitrate reductase, root activity, vitamin C, capsaicin, and nutrient uptakes of nitrogen（N）, phosphorus（P） and potassium（K） during various stages of its growth were determined. Compared with CK, when the water supply pressure was controlled at –5 to –15 k Pa in the experiment, the total water consumption of C. annuum L. reduced by 53.42 to 67.75%, the total water consumption intensity reduced by 54.29 to 67.14%, and the water use efficiency increased by 12.66 to 124.67%. The N accumulation in a single strain of C. annuum L. from the color turning stage to the red ripe stage increased by 15.99 to 100.55%, respectively, compared with that of CK; the P accumulation increased by 20.47 to 154.00% relative to that of CK, and the K accumulation increased by 64.92 to 144.9% compared with that of CK. Compared with CK, C. annuum L. yield was remarkably improved by 13.79% at T1, and contents of vitamin C, capsaicin as well as carotenoids at all growth stages were enhanced by 13.42–147.01%, 11.54–71.01%, and 41.1–568.06%, respectively. Nitrate reductase activity, root activity and chlorophyll（a＋b） were markedly increased by 335.78–500%, 79.6–140.68% and 114.95–676.19%, respectively, from immature stage to full ripe stage. Adopting the continuous negative pressure water supply for C. annuum L. has a significant water-saving effect, and the water supply pressure being stable at –5 k Pa contributes to its growth and development, improves yield, enhances root activity, promotes nutrient uptake, and improves its quality, thus achieving the effects of water conservation, high yield, high quality and high efficiency.
文摘Presented a new coal dust control program that was airtight negative pressure dust-control technology at the transpersite,combining with analysis with the movement of air currents and numerical simulation of gas-solid flow at the transpersite,and proved the mechanism of precipitation and proliferation for coal dust-controlt in theory.The technol- ogy has made good economic results at the Heidaigou Clean Plant,not only dust concen- tration control within 10 mg/m^3 to the work site,but also substantial energy savings and cost savings.
基金the National Standardization Project of TCM(ZYBZH-C-TJ-55)and National Science and Technology Major Project(2018ZX09201011-002).
文摘The negative pressure conical fluidized bed is widely used in the pharmaceutical industry.In this study,experiments based on the negative pressure conical fluidized bed are carried out by changing the material mass and particle size.The pressure fluctuation signals are analyzed by the time and the frequency domain methods.A method for absolutely characterizing the degree of the energy concentration at the main frequency is proposed,where the calculation is to divide the original power spectrum by the average signal power.A phenomenon where the gas velocity curve temporarily stops growing is observed when the material mass is light,and the particle size is small.The standard deviation and kurtosis both rapidly change at the minimum fluidization velocity and thus can be used to determine the flow regime,and the variation rule of the kurtosis is independent of both the material mass and particle size.In the initial fluidization stage,the dominant pressure signal comes from the material movement;with the increase in the gas velocity,the power of a 2.5 Hz signal continues to increase.A method of dividing the main frequency by the average cycle frequency can conveniently determine the fluidized state,and a novel concept called stable fluidized zone proposed in this paper can be obtained.Controlling the gas velocity within the stable fluidized zone ensures that the fluidized bed consistently remains in a stable fluidized state.
文摘BACKGROUND Thermal injuries on free transferred or replanted tissues resulting from loss of sensibility are an infrequent occurrence.They require immediate and appropriate management before they progress to an irreversible condition.Although negative pressure wound therapy(NPWT)can prevent wound progression by increasing microcirculation,the inappropriate application of NPWT on complicationthreatened transferred and replanted tissues can induce an adverse effect.CASE SUMMARY A 48-year-old woman who underwent immediate breast reconstruction with a deep inferior epigastric artery perforator free flap.While applying a heating pad directly to the flap site,she sustained a deep second to third-degree contact burn over 30%of the transferred flap on postoperative 7 d.As the necrotic changes had progressed,we applied an NPWT dressing over the burned area after en-bloc debridement of the transferred tissues on postoperative 21 d.After 4 d of NPWT application,the exposed fatty tissues of the flap changed to dry and browncolored necrotic tissues.Upon further debridement,we noted that the wound gradually reached total necrosis with a collapsed vascular pedicle of deep inferior epigastric artery.CONCLUSION Although NPWT has been shown to be successful for treating various wound types,the significant risk of NPWT application in short-lasting reconstructed flap wounds after thermal injury should be reminded.
文摘A series of experiments on a solid feed system was performed to investigate the effect of negative pressure gradient on the gas-solid flow pattern and hydrodynamic characteristics.Based on the non-fluidized gas-solid two phase flow and particulate mechanics in the standpipe,a method for predicting the pressure of the air passing through the recycle chamber and the pressure drop through the loop seal slit in these systems is also presented.The predicted pressure profile along the negative pressure gradient from the proposed model exhibits a good agreement with the experimental data.The experimental data show that the gas flow in the standpipe is always upward in the negative pressure gradients,while the direction ofthe superficial gas velocity through the recycle chamber of the loop seal does not affect the pressure drop in standpipe.It increases with an increasing negative pressure gradient.
基金Supported by National Natural Science Foundation of China(No. 51109160)National High Technology Research and Development Program of China ("863" Program, No. 2012AA051705)International Science and Technology Cooperation Program of China (No. 2012DFA70490)
文摘Cover-bearing-type bucket foundation for offshore wind turbines has been paid more and more attention due to its low cost and great bearing capacity. In order to ensure the cover-bearing mode, the muddy soil inside the bucket foundation should be reinforced by some soil consolidation methods, such as negative pressure and electro-osmosis. Firstly, tests were conducted to obtain the reasonable current density. Meanwhile, to improve the electro-osmotic speed and effectiveness, other factors such as intermittent power and layout of electrode, were also studied in the tests. Then, the soil reinforcing tests by negative pressure combined with electro-osmosis were performed for the muddy soil consolidation inside the bucket foundation. The results showed that soil reinforcement by negative pressure was quicker and more obvious during the early phase, and electro-osmotic method can affect more range of soil by rational arrangement of electrodes. Compared with negative pressure, the electro-osmotic method was a continuous and relatively slow process of reinforcement, which was complementary to the negative pressure method. The voltage value of electro-osmosis had little effect on the muddy soil reinforcement inside the bucket foundation, and 1.5 A was chosen as the most reasonable current value for scale model testing in the electro-osmotic method.
