Dear Editor,The latest Visian implantable collamer lens(ICL)with a central port design(Aquaport;model V4c)obviates the necessity for preoperative laser iridotomy or intraoperative iridectomy by allowing the free flow ...Dear Editor,The latest Visian implantable collamer lens(ICL)with a central port design(Aquaport;model V4c)obviates the necessity for preoperative laser iridotomy or intraoperative iridectomy by allowing the free flow of the aqueous humor between the sides of the intraocular lens.The design of Aquaport can also eliminate the complications associated with iridotomy and iridectomy.Therefore,the V4c ICL has the potential to significantly reduce the risk of pupillary block compared to its predecessors.展开更多
BACKGROUND A major cause of mortality in the coronavirus disease 2019(COVID-19)pandemic was acute respiratory distress syndrome(ARDS).Currently,moderate to severe ARDS induced by COVID-19(COVID ARDS)and other viral an...BACKGROUND A major cause of mortality in the coronavirus disease 2019(COVID-19)pandemic was acute respiratory distress syndrome(ARDS).Currently,moderate to severe ARDS induced by COVID-19(COVID ARDS)and other viral and non-viral etiologies are treated by traditional ARDS protocols that recommend 12-16 hours of prone position ventilation(PPV)with neuromuscular blocking agents(NMBA)and a trial of inhaled vasodilators(IVd)if oxygenation does not improve.However,debate on the efficacy of adjuncts to PPV and low tidal volume ventilation persists and evidence about the benefits of IVd/NMBA in COVID ARDS is sparse.In our multi-center retrospective review,we evaluated the impact of PPV,IVd,and NMBA on outcomes and lung mechanics in COVID ARDS patients with moderate to severe ARDS.AIM To evaluate the impact of PPV used alone or in combination with pulmonary IVd and/or NMBA in mechanically ventilated patients with moderate to severe ARDS during the COVID-19 pandemic.METHODS A retrospective study at two tertiary academic medical centers compared outcomes between COVID ARDS patients receiving PPV and patients in the supine position.PPV patients were divided based on concurrent use of ARDS adjunct therapies resulting in four subgroups:(1)PPV alone;(2)PPV and IVd;(3)PPV and NMBA;and(4)PPV,IVd,and NMBA.Primary outcomes were hospital and intensive care unit(ICU)length of stay(LOS),mortality,and venovenous extracorporeal membrane oxygenation(VV-ECMO)status.Secondary outcomes included changes in lung mechanics at 24-hour intervals for 7 days.RESULTS Total 114 patients were included in this study.Baseline respiratory parameters and Sequential Organ Failure Assessment scores were significantly worse in the PPV group.ICU LOS and LOS were significantly longer for patients who were proned,but no mortality benefit or difference in VV-ECMO status was found.Among the subgroups,no difference in primary outcomes were found.In the secondary analysis,PPV was associated with a significant improvement in arterial oxygen partial pressure(PaO_(2))/fractional inspired oxygen(FiO_(2))(P/F)ratio from day 1 to day 4(P<0.05)and higher driving pressures day 5 to day 7(P<0.05).The combination of PPV and IVd together resulted in improvements in P/F ratio from day 1 to day 7 and plateau pressure on day 4 and day 6(P<0.05).PPV with NMBA was not associated with improvements in any of the secondary outcomes.The use of all three rescue therapies together resulted in improvements in lung compliance on day 2(P<0.05)but no other improvements.CONCLUSION In mechanically ventilated patients diagnosed with moderate to severe COVID ARDS,PPV and PPV with the addition of IVd produced a significant and sustained increase in P/F ratio.The combination of PPV,IVd and NMBA improved compliance however this did not reach significance.Mortality and LOS did not improve with adjunct therapies.Further research is warranted to determine the efficacy of these therapies alone and in combination in the treatment of COVID ARDS.展开更多
With a history of more than 100 years, Chuquicamata has become one of the largest open pits in the world. Its current depth of 1100 m, length of 4500 m and width of 3000 m, resulting in haulage distances of over 11,00...With a history of more than 100 years, Chuquicamata has become one of the largest open pits in the world. Its current depth of 1100 m, length of 4500 m and width of 3000 m, resulting in haulage distances of over 11,000 m from pit bottom to the processing plant or waste dumps, with waste/ore ratio greater than 4 and much lower grades, are effectively determining its profitable limit by the end of this decade. Currently, there are over 4300 Mt of geological resources containing 0.7% of copper and 340 ppm (1 ppm = 1 g/t) of molybdenum below the final pit shell. The corresponding orebody geometry is 3000 m northsouth, 300-800 m eastwest and the drilling campaign suggested the existence of more than 900 m of mineable ore from the final pit bottom. This is in spite of the fact that the Chuquicamata orebody is still open at depth. The business case to continue with the mining of the Chuquicamata orebody is to change from the current large open pit to a novel macroblock variant block caving geometry. This requires a production rate of 140,000 t/d (50 Mt per annum), with a continuous material handling system to achieve the 7-year ramp-up to full production. The resolution of a number of known technical, operational and logistical challenges outside current industry practises which Chuquicamata will face over its projected 40-year mine life is therefore essential. These challenges include simultaneous operations of open pit and underground macroblocks and from the initial lift to the second lift, rapid ramp-up and optimum sequencing of the planned macroblocks, early dilution from the west fault and late dilution from potential slope failures, and the potential for major operational hazards. An equally important issue to be addressed is cultural given that the mining history in the northern region of Chile, which includes Chuquicamata, is predominantly open pit. This paper presents a synopsis of the main challenges that the Chuquicamata underground project will face in order to meet the objectives of its corresponding business case. Those discussed and how they were resolved are: simultaneous operations, rapid ramp-up and optimum sequencing of the planned macroblocks, and early and late dilutions. The project is an example of the fact that there are no recipes or cook books in cave mining.展开更多
Based on the coalbed methane(CBM)/coal-rock gas(CRG)geological,geophysical,and experimental testing data from the Daji block in the Ordos Basin,the coal-forming and hydrocarbon generation&accumulation characterist...Based on the coalbed methane(CBM)/coal-rock gas(CRG)geological,geophysical,and experimental testing data from the Daji block in the Ordos Basin,the coal-forming and hydrocarbon generation&accumulation characteristics across different zones were dissected,and the key factors controlling the differential CBM/CRG enrichment were identified.The No.8 coal seam of the Carboniferous Benxi Formation in the Daji block is 8-10 m thick,typically overlain by limestone.The primary hydrocarbon generation phase occurred during the Early Cretaceous.Based on the differences in tectonic evolution and CRG occurrence,and with the maximum vitrinite reflectance of 2.0%and burial depth of 1800 m as boundaries,the study area is divided into deeply buried and deeply preserved,deeply buried and shallowly preserved,and shallowly buried and shallowly preserved zones.The deeply buried and deeply preserved zone contains gas content of 22-35 m^(3)/t,adsorbed gas saturation of 95%-100%,and formation water with total dissolved solid(TDS)higher than 50000 mg/L.This zone features structural stability and strong sealing capacity,with high gas production rates.The deeply buried and shallowly preserved zone contains gas content of 16-20 m^(3)/t,adsorbed gas saturation of 80%-95%,and formation water with TDS of 5000-50000 mg/L.This zone exhibits localized structural modification and hydrodynamic sealing,with moderate gas production rate.The shallowly buried and shallowly preserved zone contains gas content of 8-16 m^(3)/t,adsorbed gas saturation of 50%-70%,and formation water with TDS lower than 5000 mg/L.This zone experienced intense uplift,resulting in poor sealing and secondary alteration of the primary gas reservoir,with partial adsorbed gas loss,and low gas production rate.A depositional unification and structural divergence model is proposed,that is,although coal seams across the basin experienced broadly similar depositional and tectonic histories,differences in tectonic intensity have led to spatial heterogeneity in the maximum burial depth(i.e.,thermal maturity of coal)and current burial depth and occurrence of CRG(i.e.,gas content and occurrence state).The research results provide valuable guidance for advancing the theoretical understanding of CBM/CRG enrichment and for improving exploration and development practices.展开更多
BACKGROUND Chest physiotherapy and incentive spirometry,essential for pulmonary care,can exacerbate acute post-thoracotomy pain.Pain relief is,therefore,essential to facilitate early mobilization.This study evaluated ...BACKGROUND Chest physiotherapy and incentive spirometry,essential for pulmonary care,can exacerbate acute post-thoracotomy pain.Pain relief is,therefore,essential to facilitate early mobilization.This study evaluated the analgesic efficacy of unilateral continuous erector spinae block(ESB)compared to thoracic epidural analgesia(TEA)in terms of quality of pain relief and perioperative hemodynamic changes.AIM To compare the analgesic efficacy of continuous ultrasound-guided unilateral ESB and thoracic epidural in patients undergoing antero-lateral thoracotomy.METHODS This prospective,observational study was conducted at a tertiary care hospital of central India.Sixty-eight adult patients of either gender,posted for elective thoracic surgeries requiring one lung ventilation,were allocated to either TEA(n=34)or ESB(n=34)group,based on the attending anesthesiologist’s expertise.Continuous data were analyzed by independent t-tests,and categorical data byχ2 tests.RESULTS The proportion of patients requiring rescue opioids within 24 hours post-extubation was similar between the two group.Resting numerical rating scale scores(0 hour,6 hours,and 72 hours post-extubation)were significantly higher in the ESB group compared to the TEA group[1.70±1.03 vs 1.05±0.77(P=0.004);1.64±0.98 vs 1.2±0.88(P=0.05);3.2±1.07 vs 2.61±0.92(P=0.013)].Dynamic numerical rating scale scores and post-extubation mean arterial pressures were also higher in the ESB group.Additionally,block performance time was significantly longer in the ESB group(16.58±3.66 vs 13.84±2.88,P=0.001).CONCLUSION The two techniques provided similar opioid-sparing effects following antero-lateral thoracotomy,though TEA exhibited a superior analgesic efficacy at the expense of increased hemodynamic instability requiring vasopressor support.展开更多
Dear Editor,In this case,we discuss a teenager who experienced severe eye pain and elevated intraocular pressure(IOP)caused by reverse pupillary block,which was successfully resolved using Neodymium-doped yttrium alum...Dear Editor,In this case,we discuss a teenager who experienced severe eye pain and elevated intraocular pressure(IOP)caused by reverse pupillary block,which was successfully resolved using Neodymium-doped yttrium aluminum garnet(Nd:YAG)laser peripheral iridotomy(LPI).展开更多
A double-tapered AlGaN electron blocking layer(EBL)is proposed to apply in a deep ultraviolet semiconductor laser diode.Compared with the inverse double-tapered EBL,the laser with the double-tapered EBL shows a higher...A double-tapered AlGaN electron blocking layer(EBL)is proposed to apply in a deep ultraviolet semiconductor laser diode.Compared with the inverse double-tapered EBL,the laser with the double-tapered EBL shows a higher slope efficiency,which indicates that effective enhancement in the transportation of electrons and holes is achieved.Particularly,comparisons among the double-tapered EBL,the inverse double-tapered EBL,the singletapered EBL and the inverse single-tapered EBL show that the double-tapered EBL has the best performance in terms of current leakage.展开更多
A novel low-complexity iterative receiver for multiuser space frequency block coding (SFBC) system was proposed in this paper. Unlike the conventional linear minimum mean square error (MMSE) detector, which requires m...A novel low-complexity iterative receiver for multiuser space frequency block coding (SFBC) system was proposed in this paper. Unlike the conventional linear minimum mean square error (MMSE) detector, which requires matrix inversion at each iteration, the soft-in soft-out (SISO) detector is simply a parallel interference cancellation (PIC)-matched filter (MF) operation. The probability density function (PDF) of PIC-MF detector output is approximated as Gaussian, whose variance is calculated with a priori information fed back from the channel decoder. With this approximation, the log likelihood ratios (LLRs) of transmitted bits are under-estimated. Then the LLRs are multiplied by a constant factor to achieve a performance gain. The constant factor is optimized according to extrinsic information transfer (EXIT) chart of the SISO detector. Simulation results show that the proposed iterative receiver can significantly improve the system performance and converge to the matched filter bound (MFB) with low computational complexity at high signal-to-noise ratios (SNRs).展开更多
The most commonly used method for assessing the hydraulic erodibility of rock is Annandale's method.This method is based on a correlation between the erosive force of flowing water and the capacity of rock resista...The most commonly used method for assessing the hydraulic erodibility of rock is Annandale's method.This method is based on a correlation between the erosive force of flowing water and the capacity of rock resistance. This capacity is evaluated using Kirsten's index, which was initially developed to evaluate the excavatability of earth materials. For rocky material, this index is determined according to certain geomechanical factors related to intact rock and rock mass, such as compressive strength of intact rock, rock block size, discontinuity shear strength and relative block structure. To quantify the relative block structure, Kirsten(1982) developed a mathematical expression that accounts for the shape and orientation of the blocks relative to the direction of flow. Kirsten's initial concept for assessing the relative block structure considers that the geological formation is mainly fractured by two joint sets forming an orthogonally fractured system. An adjusted concept is proposed to determine the relative block structure when the fractured system is non-orthogonal where the angle between the planes of the two joint sets is greater or less than 90°. An analysis of the proposed relative block structure rating shows that considering a non-orthogonally fractured system has a significant effect on Kirsten's index and, as a consequence, on the assessment of the hydraulic erodibility of rock.展开更多
BACKGROUND Abdominal aortic aneurysm(AAA)repair often involves significant postoperative pain,traditionally managed with systemic opioids,which can cause undesirable side effects.This case report explores the novel us...BACKGROUND Abdominal aortic aneurysm(AAA)repair often involves significant postoperative pain,traditionally managed with systemic opioids,which can cause undesirable side effects.This case report explores the novel use of a surgically-initiated rectus sheath block with a catheter-over-needle assembly for pain management in AAA repair.CASE SUMMARY A 67-year-old female with hypertension and previous aortic dissection underwent elective open repair of an infrarenal AAA,which had grown from 3.4 cm to 4.3 cm over 14 months.A rectus sheath block was initiated surgically for postoperative pain control.The patient reported low pain scores and did not require systemic intravenous opioids,enabling early ambulation and discharge on postoperative day seven without complications.By preventing complications of systemic opi-oids,the method indicating a promising direction for postoperative pain management in major vascular surgeries.CONCLUSION Surgically-initiated rectus sheath block as a valuable tool for managing postoperative pain in AAA repair.展开更多
With the continuous development of artificial intelligence and machine learning techniques,there have been effective methods supporting the work of dermatologist in the field of skin cancer detection.However,object si...With the continuous development of artificial intelligence and machine learning techniques,there have been effective methods supporting the work of dermatologist in the field of skin cancer detection.However,object significant challenges have been presented in accurately segmenting melanomas in dermoscopic images due to the objects that could interfere human observations,such as bubbles and scales.To address these challenges,we propose a dual U-Net network framework for skin melanoma segmentation.In our proposed architecture,we introduce several innovative components that aim to enhance the performance and capabilities of the traditional U-Net.First,we establish a novel framework that links two simplified U-Nets,enabling more comprehensive information exchange and feature integration throughout the network.Second,after cascading the second U-Net,we introduce a skip connection between the decoder and encoder networks,and incorporate a modified receptive field block(MRFB),which is designed to capture multi-scale spatial information.Third,to further enhance the feature representation capabilities,we add a multi-path convolution block attention module(MCBAM)to the first two layers of the first U-Net encoding,and integrate a new squeeze-and-excitation(SE)mechanism with residual connections in the second U-Net.To illustrate the performance of our proposed model,we conducted comprehensive experiments on widely recognized skin datasets.On the ISIC-2017 dataset,the IoU value of our proposed model increased from 0.6406 to 0.6819 and the Dice coefficient increased from 0.7625 to 0.8023.On the ISIC-2018 dataset,the IoU value of proposed model also improved from 0.7138 to 0.7709,while the Dice coefficient increased from 0.8285 to 0.8665.Furthermore,the generalization experiments conducted on the jaw cyst dataset from Quzhou People’s Hospital further verified the outstanding segmentation performance of the proposed model.These findings collectively affirm the potential of our approach as a valuable tool in supporting clinical decision-making in the field of skin cancer detection,as well as advancing research in medical image analysis.展开更多
Accurate identification and effective support of key blocks are crucial for ensuring the stability and safety of rock slopes.The number of structural planes and rock blocks were reduced in previous studies.This impair...Accurate identification and effective support of key blocks are crucial for ensuring the stability and safety of rock slopes.The number of structural planes and rock blocks were reduced in previous studies.This impairs the ability to characterize complex rock slopes accurately and inhibits the identification of key blocks.In this paper,a knowledge-data dually driven paradigm for accurate identification of key blocks in complex rock slopes is proposed.Our basic idea is to integrate key block theory into data-driven models based on finely characterizing structural features to identify key blocks in complex rock slopes accurately.The proposed novel paradigm consists of(1)representing rock slopes as graph-structured data based on complex systems theory,(2)identifying key nodes in the graph-structured data using graph deep learning,and(3)mapping the key nodes of graph-structured data to corresponding key blocks in the rock slope.Verification experiments and real-case applications are conducted by the proposed method.The verification results demonstrate excellent model performance,strong generalization capability,and effective classification results.Moreover,the real case application is conducted on the northern slope of the Yanqianshan Iron Mine.The results show that the proposed method can accurately identify key blocks in complex rock slopes,which can provide a decision-making basis and rational recommendations for effective support and instability prevention of rock slopes,thereby ensuring the stability of rock engineering and the safety of life and property.展开更多
基金Supported by the National Key Research and Development Program(No.2019YFC1710200)the Shandong Province Pharmaceutical Technology Development Project(No.202107020970).
文摘Dear Editor,The latest Visian implantable collamer lens(ICL)with a central port design(Aquaport;model V4c)obviates the necessity for preoperative laser iridotomy or intraoperative iridectomy by allowing the free flow of the aqueous humor between the sides of the intraocular lens.The design of Aquaport can also eliminate the complications associated with iridotomy and iridectomy.Therefore,the V4c ICL has the potential to significantly reduce the risk of pupillary block compared to its predecessors.
文摘BACKGROUND A major cause of mortality in the coronavirus disease 2019(COVID-19)pandemic was acute respiratory distress syndrome(ARDS).Currently,moderate to severe ARDS induced by COVID-19(COVID ARDS)and other viral and non-viral etiologies are treated by traditional ARDS protocols that recommend 12-16 hours of prone position ventilation(PPV)with neuromuscular blocking agents(NMBA)and a trial of inhaled vasodilators(IVd)if oxygenation does not improve.However,debate on the efficacy of adjuncts to PPV and low tidal volume ventilation persists and evidence about the benefits of IVd/NMBA in COVID ARDS is sparse.In our multi-center retrospective review,we evaluated the impact of PPV,IVd,and NMBA on outcomes and lung mechanics in COVID ARDS patients with moderate to severe ARDS.AIM To evaluate the impact of PPV used alone or in combination with pulmonary IVd and/or NMBA in mechanically ventilated patients with moderate to severe ARDS during the COVID-19 pandemic.METHODS A retrospective study at two tertiary academic medical centers compared outcomes between COVID ARDS patients receiving PPV and patients in the supine position.PPV patients were divided based on concurrent use of ARDS adjunct therapies resulting in four subgroups:(1)PPV alone;(2)PPV and IVd;(3)PPV and NMBA;and(4)PPV,IVd,and NMBA.Primary outcomes were hospital and intensive care unit(ICU)length of stay(LOS),mortality,and venovenous extracorporeal membrane oxygenation(VV-ECMO)status.Secondary outcomes included changes in lung mechanics at 24-hour intervals for 7 days.RESULTS Total 114 patients were included in this study.Baseline respiratory parameters and Sequential Organ Failure Assessment scores were significantly worse in the PPV group.ICU LOS and LOS were significantly longer for patients who were proned,but no mortality benefit or difference in VV-ECMO status was found.Among the subgroups,no difference in primary outcomes were found.In the secondary analysis,PPV was associated with a significant improvement in arterial oxygen partial pressure(PaO_(2))/fractional inspired oxygen(FiO_(2))(P/F)ratio from day 1 to day 4(P<0.05)and higher driving pressures day 5 to day 7(P<0.05).The combination of PPV and IVd together resulted in improvements in P/F ratio from day 1 to day 7 and plateau pressure on day 4 and day 6(P<0.05).PPV with NMBA was not associated with improvements in any of the secondary outcomes.The use of all three rescue therapies together resulted in improvements in lung compliance on day 2(P<0.05)but no other improvements.CONCLUSION In mechanically ventilated patients diagnosed with moderate to severe COVID ARDS,PPV and PPV with the addition of IVd produced a significant and sustained increase in P/F ratio.The combination of PPV,IVd and NMBA improved compliance however this did not reach significance.Mortality and LOS did not improve with adjunct therapies.Further research is warranted to determine the efficacy of these therapies alone and in combination in the treatment of COVID ARDS.
文摘With a history of more than 100 years, Chuquicamata has become one of the largest open pits in the world. Its current depth of 1100 m, length of 4500 m and width of 3000 m, resulting in haulage distances of over 11,000 m from pit bottom to the processing plant or waste dumps, with waste/ore ratio greater than 4 and much lower grades, are effectively determining its profitable limit by the end of this decade. Currently, there are over 4300 Mt of geological resources containing 0.7% of copper and 340 ppm (1 ppm = 1 g/t) of molybdenum below the final pit shell. The corresponding orebody geometry is 3000 m northsouth, 300-800 m eastwest and the drilling campaign suggested the existence of more than 900 m of mineable ore from the final pit bottom. This is in spite of the fact that the Chuquicamata orebody is still open at depth. The business case to continue with the mining of the Chuquicamata orebody is to change from the current large open pit to a novel macroblock variant block caving geometry. This requires a production rate of 140,000 t/d (50 Mt per annum), with a continuous material handling system to achieve the 7-year ramp-up to full production. The resolution of a number of known technical, operational and logistical challenges outside current industry practises which Chuquicamata will face over its projected 40-year mine life is therefore essential. These challenges include simultaneous operations of open pit and underground macroblocks and from the initial lift to the second lift, rapid ramp-up and optimum sequencing of the planned macroblocks, early dilution from the west fault and late dilution from potential slope failures, and the potential for major operational hazards. An equally important issue to be addressed is cultural given that the mining history in the northern region of Chile, which includes Chuquicamata, is predominantly open pit. This paper presents a synopsis of the main challenges that the Chuquicamata underground project will face in order to meet the objectives of its corresponding business case. Those discussed and how they were resolved are: simultaneous operations, rapid ramp-up and optimum sequencing of the planned macroblocks, and early and late dilutions. The project is an example of the fact that there are no recipes or cook books in cave mining.
基金Supported by the China National Science and Technology Major Project(2025ZD1405700)CNPC Science and Technology Project(2023YQX20117).
文摘Based on the coalbed methane(CBM)/coal-rock gas(CRG)geological,geophysical,and experimental testing data from the Daji block in the Ordos Basin,the coal-forming and hydrocarbon generation&accumulation characteristics across different zones were dissected,and the key factors controlling the differential CBM/CRG enrichment were identified.The No.8 coal seam of the Carboniferous Benxi Formation in the Daji block is 8-10 m thick,typically overlain by limestone.The primary hydrocarbon generation phase occurred during the Early Cretaceous.Based on the differences in tectonic evolution and CRG occurrence,and with the maximum vitrinite reflectance of 2.0%and burial depth of 1800 m as boundaries,the study area is divided into deeply buried and deeply preserved,deeply buried and shallowly preserved,and shallowly buried and shallowly preserved zones.The deeply buried and deeply preserved zone contains gas content of 22-35 m^(3)/t,adsorbed gas saturation of 95%-100%,and formation water with total dissolved solid(TDS)higher than 50000 mg/L.This zone features structural stability and strong sealing capacity,with high gas production rates.The deeply buried and shallowly preserved zone contains gas content of 16-20 m^(3)/t,adsorbed gas saturation of 80%-95%,and formation water with TDS of 5000-50000 mg/L.This zone exhibits localized structural modification and hydrodynamic sealing,with moderate gas production rate.The shallowly buried and shallowly preserved zone contains gas content of 8-16 m^(3)/t,adsorbed gas saturation of 50%-70%,and formation water with TDS lower than 5000 mg/L.This zone experienced intense uplift,resulting in poor sealing and secondary alteration of the primary gas reservoir,with partial adsorbed gas loss,and low gas production rate.A depositional unification and structural divergence model is proposed,that is,although coal seams across the basin experienced broadly similar depositional and tectonic histories,differences in tectonic intensity have led to spatial heterogeneity in the maximum burial depth(i.e.,thermal maturity of coal)and current burial depth and occurrence of CRG(i.e.,gas content and occurrence state).The research results provide valuable guidance for advancing the theoretical understanding of CBM/CRG enrichment and for improving exploration and development practices.
文摘BACKGROUND Chest physiotherapy and incentive spirometry,essential for pulmonary care,can exacerbate acute post-thoracotomy pain.Pain relief is,therefore,essential to facilitate early mobilization.This study evaluated the analgesic efficacy of unilateral continuous erector spinae block(ESB)compared to thoracic epidural analgesia(TEA)in terms of quality of pain relief and perioperative hemodynamic changes.AIM To compare the analgesic efficacy of continuous ultrasound-guided unilateral ESB and thoracic epidural in patients undergoing antero-lateral thoracotomy.METHODS This prospective,observational study was conducted at a tertiary care hospital of central India.Sixty-eight adult patients of either gender,posted for elective thoracic surgeries requiring one lung ventilation,were allocated to either TEA(n=34)or ESB(n=34)group,based on the attending anesthesiologist’s expertise.Continuous data were analyzed by independent t-tests,and categorical data byχ2 tests.RESULTS The proportion of patients requiring rescue opioids within 24 hours post-extubation was similar between the two group.Resting numerical rating scale scores(0 hour,6 hours,and 72 hours post-extubation)were significantly higher in the ESB group compared to the TEA group[1.70±1.03 vs 1.05±0.77(P=0.004);1.64±0.98 vs 1.2±0.88(P=0.05);3.2±1.07 vs 2.61±0.92(P=0.013)].Dynamic numerical rating scale scores and post-extubation mean arterial pressures were also higher in the ESB group.Additionally,block performance time was significantly longer in the ESB group(16.58±3.66 vs 13.84±2.88,P=0.001).CONCLUSION The two techniques provided similar opioid-sparing effects following antero-lateral thoracotomy,though TEA exhibited a superior analgesic efficacy at the expense of increased hemodynamic instability requiring vasopressor support.
文摘Dear Editor,In this case,we discuss a teenager who experienced severe eye pain and elevated intraocular pressure(IOP)caused by reverse pupillary block,which was successfully resolved using Neodymium-doped yttrium aluminum garnet(Nd:YAG)laser peripheral iridotomy(LPI).
基金Supported by the National Key Research and Development Program under Grant No 2016YFE0118400the Key Project of Science and Technology of Henan Province under Grant No 172102410062+1 种基金the National Natural Science Foundation of China under Grant No 61176008the National Natural Science Foundation of China Henan Provincial Joint Fund Key Project under Grant No U1604263
文摘A double-tapered AlGaN electron blocking layer(EBL)is proposed to apply in a deep ultraviolet semiconductor laser diode.Compared with the inverse double-tapered EBL,the laser with the double-tapered EBL shows a higher slope efficiency,which indicates that effective enhancement in the transportation of electrons and holes is achieved.Particularly,comparisons among the double-tapered EBL,the inverse double-tapered EBL,the singletapered EBL and the inverse single-tapered EBL show that the double-tapered EBL has the best performance in terms of current leakage.
基金The Science and Technology Committee of Shanghai Municipality ( No 06DZ15013,No03DZ15010)
文摘A novel low-complexity iterative receiver for multiuser space frequency block coding (SFBC) system was proposed in this paper. Unlike the conventional linear minimum mean square error (MMSE) detector, which requires matrix inversion at each iteration, the soft-in soft-out (SISO) detector is simply a parallel interference cancellation (PIC)-matched filter (MF) operation. The probability density function (PDF) of PIC-MF detector output is approximated as Gaussian, whose variance is calculated with a priori information fed back from the channel decoder. With this approximation, the log likelihood ratios (LLRs) of transmitted bits are under-estimated. Then the LLRs are multiplied by a constant factor to achieve a performance gain. The constant factor is optimized according to extrinsic information transfer (EXIT) chart of the SISO detector. Simulation results show that the proposed iterative receiver can significantly improve the system performance and converge to the matched filter bound (MFB) with low computational complexity at high signal-to-noise ratios (SNRs).
基金the organizations that have funded this project:the Natural Sciences and Engineering Research Council of Canada(Grant No.498020-16)Hydro-Quebec(NC-525700)Mitacs Accelerate Program(Grant Ref.IT10008)
文摘The most commonly used method for assessing the hydraulic erodibility of rock is Annandale's method.This method is based on a correlation between the erosive force of flowing water and the capacity of rock resistance. This capacity is evaluated using Kirsten's index, which was initially developed to evaluate the excavatability of earth materials. For rocky material, this index is determined according to certain geomechanical factors related to intact rock and rock mass, such as compressive strength of intact rock, rock block size, discontinuity shear strength and relative block structure. To quantify the relative block structure, Kirsten(1982) developed a mathematical expression that accounts for the shape and orientation of the blocks relative to the direction of flow. Kirsten's initial concept for assessing the relative block structure considers that the geological formation is mainly fractured by two joint sets forming an orthogonally fractured system. An adjusted concept is proposed to determine the relative block structure when the fractured system is non-orthogonal where the angle between the planes of the two joint sets is greater or less than 90°. An analysis of the proposed relative block structure rating shows that considering a non-orthogonally fractured system has a significant effect on Kirsten's index and, as a consequence, on the assessment of the hydraulic erodibility of rock.
基金Supported by the Taichung Veterans General Hospital,No.TCVGH-1125401B.
文摘BACKGROUND Abdominal aortic aneurysm(AAA)repair often involves significant postoperative pain,traditionally managed with systemic opioids,which can cause undesirable side effects.This case report explores the novel use of a surgically-initiated rectus sheath block with a catheter-over-needle assembly for pain management in AAA repair.CASE SUMMARY A 67-year-old female with hypertension and previous aortic dissection underwent elective open repair of an infrarenal AAA,which had grown from 3.4 cm to 4.3 cm over 14 months.A rectus sheath block was initiated surgically for postoperative pain control.The patient reported low pain scores and did not require systemic intravenous opioids,enabling early ambulation and discharge on postoperative day seven without complications.By preventing complications of systemic opi-oids,the method indicating a promising direction for postoperative pain management in major vascular surgeries.CONCLUSION Surgically-initiated rectus sheath block as a valuable tool for managing postoperative pain in AAA repair.
基金funded by Zhejiang Basic Public Welfare Research Project,grant number LZY24E060001supported by Guangzhou Development Zone Science and Technology(2021GH10,2020GH10,2023GH02)+1 种基金the University of Macao(MYRG2022-00271-FST)the Science and Technology Development Fund(FDCT)of Macao(0032/2022/A).
文摘With the continuous development of artificial intelligence and machine learning techniques,there have been effective methods supporting the work of dermatologist in the field of skin cancer detection.However,object significant challenges have been presented in accurately segmenting melanomas in dermoscopic images due to the objects that could interfere human observations,such as bubbles and scales.To address these challenges,we propose a dual U-Net network framework for skin melanoma segmentation.In our proposed architecture,we introduce several innovative components that aim to enhance the performance and capabilities of the traditional U-Net.First,we establish a novel framework that links two simplified U-Nets,enabling more comprehensive information exchange and feature integration throughout the network.Second,after cascading the second U-Net,we introduce a skip connection between the decoder and encoder networks,and incorporate a modified receptive field block(MRFB),which is designed to capture multi-scale spatial information.Third,to further enhance the feature representation capabilities,we add a multi-path convolution block attention module(MCBAM)to the first two layers of the first U-Net encoding,and integrate a new squeeze-and-excitation(SE)mechanism with residual connections in the second U-Net.To illustrate the performance of our proposed model,we conducted comprehensive experiments on widely recognized skin datasets.On the ISIC-2017 dataset,the IoU value of our proposed model increased from 0.6406 to 0.6819 and the Dice coefficient increased from 0.7625 to 0.8023.On the ISIC-2018 dataset,the IoU value of proposed model also improved from 0.7138 to 0.7709,while the Dice coefficient increased from 0.8285 to 0.8665.Furthermore,the generalization experiments conducted on the jaw cyst dataset from Quzhou People’s Hospital further verified the outstanding segmentation performance of the proposed model.These findings collectively affirm the potential of our approach as a valuable tool in supporting clinical decision-making in the field of skin cancer detection,as well as advancing research in medical image analysis.
基金supported by the National Natural Science Foundation of China(Grant Nos.42277161,42230709).
文摘Accurate identification and effective support of key blocks are crucial for ensuring the stability and safety of rock slopes.The number of structural planes and rock blocks were reduced in previous studies.This impairs the ability to characterize complex rock slopes accurately and inhibits the identification of key blocks.In this paper,a knowledge-data dually driven paradigm for accurate identification of key blocks in complex rock slopes is proposed.Our basic idea is to integrate key block theory into data-driven models based on finely characterizing structural features to identify key blocks in complex rock slopes accurately.The proposed novel paradigm consists of(1)representing rock slopes as graph-structured data based on complex systems theory,(2)identifying key nodes in the graph-structured data using graph deep learning,and(3)mapping the key nodes of graph-structured data to corresponding key blocks in the rock slope.Verification experiments and real-case applications are conducted by the proposed method.The verification results demonstrate excellent model performance,strong generalization capability,and effective classification results.Moreover,the real case application is conducted on the northern slope of the Yanqianshan Iron Mine.The results show that the proposed method can accurately identify key blocks in complex rock slopes,which can provide a decision-making basis and rational recommendations for effective support and instability prevention of rock slopes,thereby ensuring the stability of rock engineering and the safety of life and property.
