In this paper, we studied the process of dissociation unimolecular of the evaporation of H+2n+1 hydrogen clusters according to size, using the Rice-Ramsperger-Kassel-Marcus (RRKM) theory. The rate constants k(E) were ...In this paper, we studied the process of dissociation unimolecular of the evaporation of H+2n+1 hydrogen clusters according to size, using the Rice-Ramsperger-Kassel-Marcus (RRKM) theory. The rate constants k(E) were determined with the use of statistical theory of unimolecular reactions using various approximations. In our work, we used the products frequencies instead of transitions frequencies in the calculation of unimolecular dissociation rates obtained by three models RRKM. The agreement between the experimental cross section ratio and calculated rate ratio with direct count approximation seems to be reasonable.展开更多
The El Pintado 1 Silurian section in Seville Province,Spain,described by Loydell et al.(2015),has been ratified by the IUGS as the replacement GSSP for the base of the Telychian Stage,to replace the Cefn Cerig quarry ...The El Pintado 1 Silurian section in Seville Province,Spain,described by Loydell et al.(2015),has been ratified by the IUGS as the replacement GSSP for the base of the Telychian Stage,to replace the Cefn Cerig quarry section in the Llandovery area of Wales,which was found to be within a sedimentary mélange and therefore not a continuous section.No section other than El Pintado 1 has been found to be continuously fossiliferous across the Aeronian/Telychian boundary.展开更多
Laser pulse nonlinear transmission measurements through saturable absorbers of known absorption parameters allow the measurement of their energy density. On the other hand, nonlinear transmission measurements of laser...Laser pulse nonlinear transmission measurements through saturable absorbers of known absorption parameters allow the measurement of their energy density. On the other hand, nonlinear transmission measurements of laser pulses of known energy density through absorbing media allow their absorption parameter determination. The peak energy density w0P of second harmonic pulses of a mode-locked titanium sapphire laser at wavelength λP = 400 nm is determined by nonlinear energy transmission measurement TE through the dye ADS084BE (1,4-bis(9-ethyl-3-car-bazovinylene)-2-methoxy-5-(2’-ethyl-hexyloxy)-benzene) in tetrahydrofuran. TE(w0P) calibration curves are calculated for laser pulse peak energy density reading w0P from measured pulse energy transmissions TE. The ground-state absorption cross-section σP and the excited-state absorption cross-section σex at λP, and the number density N0 of the retinal Schiff base isoform RetA in pH 7.4 buffer of the blue-light adapted recombinant rhodopsin fragment of the histidine kinase rhodopsin HKR1 from Chlamydomonas reinhardtii were determined by picosecond titanium sapphire second harmonic laser pulse energy transmission measurement TE through RetA as a function of laser input peak energy density w0P. The complete absorption cross-section spectrum展开更多
AIM To evaluate the usefulness of frozen section diagnosis(FSD) of bile duct margins during surgery for extrahepatic cholangiocarcinoma(CCA). METHODS We retrospectively analyzed 74 consecutive patients who underwent s...AIM To evaluate the usefulness of frozen section diagnosis(FSD) of bile duct margins during surgery for extrahepatic cholangiocarcinoma(CCA). METHODS We retrospectively analyzed 74 consecutive patients who underwent surgery for extrahepatic CCA from 2012 to 2017, during which FSD of bile duct margins was performed. They consisted of 40 distant and 34 perihilar CCAs(45 and 55 bile duct margins, respectively). The diagnosis was classified into three categories: negative, borderline(biliary intraepithelial neoplasia-1 and 2, and indefinite for neoplasia), or positive. FSD in the epithelial layer, subepithelial layer, and total layer was compared with corresponding permanent section diagnosis(PSD) postoperatively.Then, association between FSD and local recurrence was analyzed with special reference to borderline.RESULTS Analysis of 100 duct margins revealed that concordance rate between FSD and PSD was 68.0% in the total layer, 69.0% in the epithelial layer, and 98.0% in the subepithelial layer. The extent of remaining biliary epithelium was comparable between FSD and PSD, and more than half of the margins lost > 50% of the entire epithelium, suggesting low quality of the samples. In FSD, the rate of negative margins decreased and that of borderline and positive margins increased according to the extent of the remaining epithelium. Diagnostic discordance between FSD and PSD was observed in 31 epithelial layers and two subepithelial layers. Alteration from borderline to negative was the most frequent(20 of the 31 epithelial layers). Patients with positive margin in the total and epithelial layers by FSD demonstrated a significantly worse local recurrence-free survival(RFS) compared with patients with borderline and negative margins, which revealed comparable local RFS. Patients with borderline and negative margins in the epithelial layer by PSD also revealed comparable local RFS. These results suggested that epithelial borderline might be regarded substantially as negative. When classifying the status of the epithelial layer either as negative or positive, concordance rates between FSD and PSD in the total, epithelial, and subepithelial layers were 95.0%, 93.0%, and 98.0%, respectively.CONCLUSION During intraoperative assessment of bile duct margin, borderline in the epithelial layer can be substantially regarded as negative, under which condition FSD is comparable to PSD.展开更多
Rapid population aging has led to an increased focus on age-related conditions such as sarcopenia.causing loss of muscle mass and strength^([1,2]). Sarcopenia is associated with adverse outcomes,including falls, funct...Rapid population aging has led to an increased focus on age-related conditions such as sarcopenia.causing loss of muscle mass and strength^([1,2]). Sarcopenia is associated with adverse outcomes,including falls, functional decline, frailty, and mortality, which can lower the quality of life and shorten lifespan^([1,2]).展开更多
Dear Editor,I am writing in response to the article“Assessment of nurses’workplace silence behavior motives:A cross-sectional study”by Alhojairi et al.published in the September 2024 issue of the International Jour...Dear Editor,I am writing in response to the article“Assessment of nurses’workplace silence behavior motives:A cross-sectional study”by Alhojairi et al.published in the September 2024 issue of the International Journal of Nursing Sciences[1].This is a letter written by a nurse with 10 years of clinical work experience and a personal interest in team dynamics.I appreciate the authors'recommendations on mitigating workplace silence among nurses to enhance clinical work development,and I believe their proposals could be expanded further.展开更多
BACKGROUND Oil-based iodinated contrast media have excellent contrast properties and are widely used for hysterosalpingographic evaluation of female infertility.On abdominal radiography and computed tomography(CT)scan...BACKGROUND Oil-based iodinated contrast media have excellent contrast properties and are widely used for hysterosalpingographic evaluation of female infertility.On abdominal radiography and computed tomography(CT)scans,their radiodensity is similar to that of metallic objects,which can sometimes lead to diagnostic confusion in the postoperative settings.In this case,retained oil-based contrast medium was observed on an abdominal radiograph following a cesarean section,making it difficult to differentiate from an intraperitoneal foreign body from surgery.The patient was a 37-year-old pregnant woman who was referred to our hospital at 32 weeks and 1 day of pregnancy due to complete placenta previa for mana-gement of pregnancy and delivery.An elective cesarean section was performed at 37 weeks and 3 days.A plain abdominal radiograph taken immediately after surgery revealed a near-round,hyperdense,mass-like shadow with a regular margin in the pelvic cavity.An intraperitoneal foreign body was suspected;therefore,an abdominal CT scan was performed.The foreign body was located on the left side of the pouch of Douglas and had a CT value of 7000 Hounsfield units,similar to that of metals.The CT value strongly suggested the presence of an artificial object.However,further inquiries with the patient and her previous physician revealed a history of hysterosalpingography.Accordingly,retained oil-based iodinated contrast medium was suspected,and observation of the object’s course was adopted.CONCLUSION When intraperitoneal foreign bodies are suspected on postoperative radiographs,the possibility of oil-based iodinated contrast medium retention should be considered.展开更多
(此课选自义务教育课程标准实验教科书《英语》(新目标)Go for it.九年级(全一册))一、设计理念:本节课的教学内容是一节完整的阅读板块,采用单词讲解,读前预测,读中利用寻读和细读的阅读策略提取文章关键信息,读后利用思维导图总结全...(此课选自义务教育课程标准实验教科书《英语》(新目标)Go for it.九年级(全一册))一、设计理念:本节课的教学内容是一节完整的阅读板块,采用单词讲解,读前预测,读中利用寻读和细读的阅读策略提取文章关键信息,读后利用思维导图总结全文信息,然后讲解文章难句的设计思路,培养学生的分析能力和阅读技能。展开更多
BACKGROUND Intrathecal bupivacaine is the traditional anesthetic drug used in spinal anesthesia for caesarean sections(CSs),but ropivacaine has emerged as a potential alter-native.This meta-analysis compares the effic...BACKGROUND Intrathecal bupivacaine is the traditional anesthetic drug used in spinal anesthesia for caesarean sections(CSs),but ropivacaine has emerged as a potential alter-native.This meta-analysis compares the efficacy and safety of intrathecal hyper-baric bupivacaine vs hyperbaric ropivacaine for cesarean sections.AIM To systematically evaluate and compare the efficacy and safety of intrathecal hyperbaric bupivacaine and hyperbaric ropivacaine for spinal anesthesia in CSs.METHODS A thorough search of electronic databases was carried out to find pertinent randomized controlled trials(RCTs)comparing intrathecal hyperbaric ropi-vacaine and hyperbaric bupivacaine during CSs.PubMed,Cochrane database,Google Scholar,and Scopus were searched,and papers from January 2000 to January 2024 were deemed eligible and filtered using predetermined inclusion and exclusion criteria.Studies were assessed for methodological quality,and data were extracted for time to adequate anesthesia(sensory and motor blockade),duration of sensory and motor block,hemodynamic changes and side effect profile.The standardized mean difference with 95%CI was used for continuous data.Dichotomous variables were assessed using the Mantel-Haenszel test and the random effect model to compute the odds ratio.RESULTS Total 8 RCTs were selected from a pool of 119 search results for meta-analysis.The meta-analysis evaluated pooled effect sizes and assessed heterogeneity among the studies.The primary objective was to compare key outcomes to identify any significant variances in efficacy and safety profiles between two local anesthetics.The analysis revealed that the difference in the onset of sensory blockade between the two local anesthetics was statistically insignificant(P=0.1586).However,the onset of motor blockade appeared to be faster with bupivacaine(P=0.03589).Additionally,the regression of sensory and motor blockade occurred earlier in the ropivacaine group.Furthermore,the duration of the first analgesic effect was shorter with a significance level of P<0.05.Regarding side effects profile,including hypotension,nausea,and shivering,the study did not observe any significant differences between the two groups.CONCLUSION This meta-analysis offers insights into the effectiveness and safety of hyperbaric bupivacaine vs ropivacaine for cesarean sections.Hyperbaric ropivacaine had a comparable safety profile and faster regression of sensory and motor blockade than hyperbaric bupivacaine,perhaps aiding early mobilization of parturient and facilitating mother-child bonding.Choosing ropivacaine may offer benefits beyond efficacy for cesarean section patients and short surgical procedures.展开更多
Foamed concrete is widely employed in highway transition sections,due to its lightweight,high-strength,and effective settlement control.It is crucial to investigate its dynamic response linked to the traffic-loading i...Foamed concrete is widely employed in highway transition sections,due to its lightweight,high-strength,and effective settlement control.It is crucial to investigate its dynamic response linked to the traffic-loading influence zone of embankment and transition section smoothness.In this study,in-situ truck tests were conducted in the road-culvert-bridge transition section to obtain the spatio-temporal response patterns.Based on the vertical response,the influence zone was ascertained.Depending on the longitudinal response,the smoothness was evaluated by equivalent dynamic stiffness(EDS)and acceleration variation rate(AVR).Furthermore,the response discrepancies of embankments with different fillings were compared.Findings reveal exponential attenuation of dynamic stress and acceleration with increasing depth.The acceleration and dynamic displacement exhibit U-shaped patterns in the culvert subsection and abrupt changes in the bridgehead subsection.The influence zone determined by the acceleration attenuation coefficient method,dynamic stress attenuation method,and stress diffusion angle method was 1.55 m,2.05 m,and 2.89 m,respectively.The maximum disparity in EDS occurs at the culvert subsection and bridge abutment,and the AVR ranges from 0 to 0.52 s^(-2).Moreover,94.1%attenuation of the dynamic stress occurred within the 1.5-meter foamed concrete embankment under the setting of 100 kN-60 km/h.展开更多
Aspects of the general Vlasov theory are examined separately as applied to a thin-walled channel section cantilever beam under free-end end loading. In particular, the flexural bending and shear that arise under trans...Aspects of the general Vlasov theory are examined separately as applied to a thin-walled channel section cantilever beam under free-end end loading. In particular, the flexural bending and shear that arise under transverse shear and axial torsional loading are each considered theoretically. These analyses involve the location of the shear centre at which transverse shear forces when applied do not produce torsion. This centre, when taken to be coincident with the centre of twist implies an equivalent reciprocal behaviour. That is, an axial torsion applied concentric with the shear centre will twist but not bend the beam. The respective bending and shear stress conversions are derived for each action applied to three aluminium alloy extruded channel sections mounted as cantilevers with a horizontal principal axis of symmetry. Bending and shear are considered more generally for other thin-walled sections when the transverse loading axes at the shear centre are not parallel to the section = s centroidal axes of principal second moments of area. The fixing at one end of the cantilever modifies the St Venant free angular twist and the free warping displacement. It is shown from the Wagner-Kappus torsion theory how the end constrained warping generates an axial stress distribution that varies with the length and across the cross-section for an axial torsion applied to the shear centre. It should be mentioned here for wider applications and validation of the Vlasov theory that attendant papers are to consider in detail bending and torsional loadings applied to other axes through each of the centroid and the web centre. Therein, both bending and twisting arise from transverse shear and axial torsion applied to each position being displaced from the shear centre. Here, the influence of the axis position upon the net axial and shear stress distributions is to be established. That is, the net axial stress from axial torsional loading is identified with the sum of axial stress due to bending and axial stress arising from constrained warping displacements at the fixing. The net shear stress distribution overlays the distributions from axial torsion and that from flexural shear under transverse loading. Both arise when transverse forces are displaced from the shear centre.展开更多
BACKGROUND Transition is a critical period for adolescents as they begin to assume responsibility for their own health.Similarly,the shift from pediatric to adult healthcare represents a vulnerable phase,marked by uni...BACKGROUND Transition is a critical period for adolescents as they begin to assume responsibility for their own health.Similarly,the shift from pediatric to adult healthcare represents a vulnerable phase,marked by unique challenges in adolescent health care.Despite its importance,only a few studies have explored healthcare transition among adolescents in Uganda.AIM To identify factors associated with the transition to adult human immunodeficiency virus(HIV)-centered care among adolescents attending HIV/AIDS clinics in Uganda.METHODS A cross-sectional mixed-methods study was conducted among 265 adolescents,randomly selected from three antiretroviral therapy(ART)clinics,using a structured questionnaire.Focus group discussions and key informant interviews were conducted.Individuals aged 10-20 years who were actively enrolled in the ART program between January 4,2022 and January 30,2023 were recruited.The primary outcome of interest was the transition to adult care.Bivariate and multivariate analyses were performed for quantitative data,while content analysis was used to analyze qualitative data.RESULTS The prevalence of transition to adult care was 40.6%.Most participants were male(53.6%)and fell within the 13-15 age group(35.6%).Multivariate logistic regression analysis identified several factors significantly associated with transition to adult care:Age group 10-12 years[prevalence ratio(PR)=2.525,95%CI:2.121-2.944,P=0.002],Age group 13-15 years(PR=1.900,95%CI:1.196-3.416,P=0.001),successful viral load suppression(PR=1.534,95%CI:1.173-1.648,P=0.016),disclosure of HIV status to relatives(PR=5.001,95%CI:3.411-3.611,P=0.000),being prepared for transitioning(PR=5.417,95%CI:3.468-7.135,P=0.041)and having skilled pediatric caregivers(PR=3.724,95%CI:2.084-4.105,P=0.005).CONCLUSION Transition to adult care among adolescents was low.Improving transition outcomes may require strengthening individual support within the family context and integrating transition-focused care into existing specialized clinical settings to enhance the delivery of adolescent-friendly services.展开更多
The neutron capture cross section for^(165)Ho was measured at the backstreaming white neutron beam line(Back-n)of the China Spallation Neutron Source(CSNS)using total energy detection systems,composed of a set of four...The neutron capture cross section for^(165)Ho was measured at the backstreaming white neutron beam line(Back-n)of the China Spallation Neutron Source(CSNS)using total energy detection systems,composed of a set of four C_(6)D_(6)scintillator detectors coupled with pulse height weighting techniques.The resonance parameters were extracted using the multilevel multichannel R-matrix code SAMMY to fit the measured capture yields of the^(165)Ho(n,γ)reaction in the neutron energy range below100 eV.Subsequently,the resonance region’s capture cross sections were reconstructed based on the obtained parameters.Furthermore,the unresolved resonance average cross section of the^(165)Ho(n,γ)reaction was determined relative to that of the standard sample^(197)Au within the neutron energy range of 2 keV to 1 MeV.The experimental data were compared with the recommended nuclear data from the ENDF/B-VIII.0 library,as well as with results of calculations performed using the TALYS-1.9 code.The comparison revealed agreement between the measured^(165)Ho(n,γ)cross sections and these data.The present results are crucial for evaluating the^(165)Ho neutron capture cross section and thus enhance the quality of evaluated nuclear data libraries.They provide valuable guidance for nuclear theoretical models and nuclear astrophysical studies.展开更多
Analyzing the mass of behind-armor debris (BAD) generated by Rolled Homogeneous Armor (RHA) subjected to normal penetration of variable cross-section Explosively Formed Projectile (EFP) is the purpose of this paper. S...Analyzing the mass of behind-armor debris (BAD) generated by Rolled Homogeneous Armor (RHA) subjected to normal penetration of variable cross-section Explosively Formed Projectile (EFP) is the purpose of this paper. So theoretical analysis, numerical simulation and experimental data are combined to analyze the influence of variable cross-section characteristic on the time history of crater radius. Moreover the relationships between time history of crater radius (as well as mass of BAD) and the thickness of RHA (from 30mm to 70 mm) and the impact velocity of EFP (1650 m/s to 1860 m/s) are also investigated. The results indicate that: 1) being compared to the variable cross-section characteristic is ignored, the theoretical time history of crater radius is in better agreement with the simulation results when the variable cross-section characteristic is considered;2) being compared to the other three conditions of plug, the theoretical mass of BAD is in the best agreement with the simulation results when the shape of plug is frustum of a cone and the angle between generatrix and bottom is 45- and the axial length of mushroom is considered.展开更多
The identification and characterization of rock types is a core activity in geology and related fields,including mining,petroleum,environmental science,industry,and construction.Traditionally,this task is performed by...The identification and characterization of rock types is a core activity in geology and related fields,including mining,petroleum,environmental science,industry,and construction.Traditionally,this task is performed by human specialists who analyze and describe the type,composition,texture,shape,and other properties of rock samples,whether collected in-situ or prepared in a laboratory.However,the process is subjective,dependent on the specialist’s experience,and time-consuming.This study proposes an artificial intelligence-based approach that combines computer vision and natural language processing to generate both textual and verbal descriptions from images of rock thin sections.A dataset of images and corresponding textual descriptions is used to train a hybrid deep learning model.Features extracted from the images using EfficientNetB7 are processed by a Transformer network to generate textual descriptions,which are then converted into verbal responses using a speech synthesis service.The experimental results show an accuracy of 0.892 and a BLEU score of 0.71.This model offers potential utility for research,professional,and academic applications and has been deployed as a web application for public use.展开更多
Objective:The objective of this study is to determine the effect of nurse-led instructional video(NLIV)on anxiety,satisfaction,and recovery among mothers admitted for cesarean section(CS).Materials and Methods:A quasi...Objective:The objective of this study is to determine the effect of nurse-led instructional video(NLIV)on anxiety,satisfaction,and recovery among mothers admitted for cesarean section(CS).Materials and Methods:A quasi-experimental design was carried out on the mothers scheduled for CS.Eighty participants were selected by a purposive sampling technique,which were divided(40 participants in each group)into an experimental group and a control group.Nurse-led informational video(NLIV)was shown to the experimental group,and routine care was provided for the control group.Modified hospital anxiety scale(HADS),scale for measuring maternal satisfaction in cesarean birth,and obstetric quality of recovery following cesarean delivery were used to assess anxiety,satisfaction,and recovery.Results:Both the experimental and control groups showed significant reductions in anxiety by the first postintervention day(P<0.001),with the experimental group experiencing a greater mean reduction(mean difference[MD]=4.37)than the control group(MD=3.35)but the intergroup difference was not statistically significant(P>0.05).The experimental group reported significantly higher satisfaction scores(175.55±9.42)on the 3rd postoperative day compared to the control group(151.93±14.89;P<0.001).Similarly,the experimental group’s recovery scores(79.90±6.24)were considerably higher than those of the control group(62.45±15.18;P<0.001).On the 3rd postintervention day,satisfaction was significantly associated with age(P<0.001),and recovery with gravidity(P<0.05).Conclusions:NLIV can be used in the preoperative period to reduce anxiety related to CS and to improve satisfaction and recovery after the CS.展开更多
Emergency cesarean section has always been a challenge for patients,surgeons,and anesthesiologists,as it endangers the safety of both parturients and fetuses.Obesity and hypertension are common among pregnant women,bu...Emergency cesarean section has always been a challenge for patients,surgeons,and anesthesiologists,as it endangers the safety of both parturients and fetuses.Obesity and hypertension are common among pregnant women,but severe obesity combined with refractory hypertension is very rare in clinical practice.The optimal anesthetic management strategy for obese pregnant women with a difficult airway and poorly controlled hypertension remains debatable.This report presents a 32-year-old woman with severe obesity and refractory hypertension at 36 weeks and 6 days of pregnancy.Owing to fetal heart rate abnormalities,she was scheduled for emergency cesarean section.Given the urgency of the fetal condition and the challenges posed by the patient's obesity for epidural puncture,the anesthesiologist opted for rapid sequence induction and tracheal intubation instead of intervertebral anesthesia.Short-acting antihypertensive medications were adminstrated preoperatively to control elevated blood pressure,and vasopressor agents were continuously infused during surgery to prevent severe hypotension induced by anesthetic drugs.The entire anesthesia and surgical procedure proceeded uneventfully,with no major adverse events observed.Both the patient and fetus achieved favorable outcomes.This case indicates that early anesthetic risk assessment and meticulous pre-delivery planning are paramount,necessitating personalized management of airway and hemodynamics to optimize outcomes in obese parturients.展开更多
Radar cross section(RCS)plays a critical role in modeling target scattering characteristics and enhancing the precision of target detection and localization in integrated sensing and communication(ISAC)systems.This pa...Radar cross section(RCS)plays a critical role in modeling target scattering characteristics and enhancing the precision of target detection and localization in integrated sensing and communication(ISAC)systems.This paper investigates the human body RCS at 26 GHz via multiangle channel measurements under different clothing conditions.Based on calibrated electromagnetic(EM)parameters,the RCS characteristics of the human body in far-field conditions are analyzed using ray-tracing(RT)simulations.Some suggestions for the design of ISAC systems are also discussed.The results provide a solid theoretical foundation and practical reference for the modeling of target scattering characteristics for ISAC channels.展开更多
To overcome the limitations of low efficiency and reliance on manual processes in the measurement of geometric parameters for bridge prefabricated components,a method based on deep learning and computer vision is deve...To overcome the limitations of low efficiency and reliance on manual processes in the measurement of geometric parameters for bridge prefabricated components,a method based on deep learning and computer vision is developed to identify the geometric parameters.The study utilizes a common precast element for highway bridges as the research subject.First,edge feature points of the bridge component section are extracted from images of the precast component cross-sections by combining the Canny operator with mathematical morphology.Subsequently,a deep learning model is developed to identify the geometric parameters of the precast components using the extracted edge coordinates from the images as input and the predefined control parameters of the bridge section as output.A dataset is generated by varying the control parameters and noise levels for model training.Finally,field measurements are conducted to validate the accuracy of the developed method.The results indicate that the developed method effectively identifies the geometric parameters of bridge precast components,with an error rate maintained within 5%.展开更多
To verify the performance of the neutron total cross-sectional spectrometer, the neutron total cross section of carbon is initially measured in the energy range of 1 eV to 20 MeV using the time-of-flight method. The m...To verify the performance of the neutron total cross-sectional spectrometer, the neutron total cross section of carbon is initially measured in the energy range of 1 eV to 20 MeV using the time-of-flight method. The measurement is performed at the Back-n white neutron source with a 76-m time-of-flight path using the China Spallation Neutron Source. A multilayer fast fission chamber with 235U and 238U is employed as the neutron detector. The diameter and thickness of the natural graphite sample are 70 mm and 40 mm, respectively. Signal waveforms are collected using a data acquisition system. Off-line data processing was used to obtain the neutron time-of-flight spectra and transmissions. The uncertainty of the counting statistics is generally approximately 3% for each bin in the energy range of 1–20 MeV. It is determined that the results for the neutron total cross section of carbon obtained using ^235U cells are in good agreement with the results obtained using 238U cells within limits of statistical uncertainty. Moreover, the measured total cross sections show good agreement with the broadening evaluated data.展开更多
文摘In this paper, we studied the process of dissociation unimolecular of the evaporation of H+2n+1 hydrogen clusters according to size, using the Rice-Ramsperger-Kassel-Marcus (RRKM) theory. The rate constants k(E) were determined with the use of statistical theory of unimolecular reactions using various approximations. In our work, we used the products frequencies instead of transitions frequencies in the calculation of unimolecular dissociation rates obtained by three models RRKM. The agreement between the experimental cross section ratio and calculated rate ratio with direct count approximation seems to be reasonable.
基金funded by project PDI2021-125585NB-I00 of the Spanish Ministry of Science,Innovation and Universities‒Agencia Estatal de Investigacion.JF thanks the Grant Agency of the Czech Republic for support of his study(GA23-06198S).
文摘The El Pintado 1 Silurian section in Seville Province,Spain,described by Loydell et al.(2015),has been ratified by the IUGS as the replacement GSSP for the base of the Telychian Stage,to replace the Cefn Cerig quarry section in the Llandovery area of Wales,which was found to be within a sedimentary mélange and therefore not a continuous section.No section other than El Pintado 1 has been found to be continuously fossiliferous across the Aeronian/Telychian boundary.
文摘Laser pulse nonlinear transmission measurements through saturable absorbers of known absorption parameters allow the measurement of their energy density. On the other hand, nonlinear transmission measurements of laser pulses of known energy density through absorbing media allow their absorption parameter determination. The peak energy density w0P of second harmonic pulses of a mode-locked titanium sapphire laser at wavelength λP = 400 nm is determined by nonlinear energy transmission measurement TE through the dye ADS084BE (1,4-bis(9-ethyl-3-car-bazovinylene)-2-methoxy-5-(2’-ethyl-hexyloxy)-benzene) in tetrahydrofuran. TE(w0P) calibration curves are calculated for laser pulse peak energy density reading w0P from measured pulse energy transmissions TE. The ground-state absorption cross-section σP and the excited-state absorption cross-section σex at λP, and the number density N0 of the retinal Schiff base isoform RetA in pH 7.4 buffer of the blue-light adapted recombinant rhodopsin fragment of the histidine kinase rhodopsin HKR1 from Chlamydomonas reinhardtii were determined by picosecond titanium sapphire second harmonic laser pulse energy transmission measurement TE through RetA as a function of laser input peak energy density w0P. The complete absorption cross-section spectrum
基金JSPS KAKENHI(No.JP16K08695)from the Ministry of Education,Culture,Sports,Science and Technology of Japan
文摘AIM To evaluate the usefulness of frozen section diagnosis(FSD) of bile duct margins during surgery for extrahepatic cholangiocarcinoma(CCA). METHODS We retrospectively analyzed 74 consecutive patients who underwent surgery for extrahepatic CCA from 2012 to 2017, during which FSD of bile duct margins was performed. They consisted of 40 distant and 34 perihilar CCAs(45 and 55 bile duct margins, respectively). The diagnosis was classified into three categories: negative, borderline(biliary intraepithelial neoplasia-1 and 2, and indefinite for neoplasia), or positive. FSD in the epithelial layer, subepithelial layer, and total layer was compared with corresponding permanent section diagnosis(PSD) postoperatively.Then, association between FSD and local recurrence was analyzed with special reference to borderline.RESULTS Analysis of 100 duct margins revealed that concordance rate between FSD and PSD was 68.0% in the total layer, 69.0% in the epithelial layer, and 98.0% in the subepithelial layer. The extent of remaining biliary epithelium was comparable between FSD and PSD, and more than half of the margins lost > 50% of the entire epithelium, suggesting low quality of the samples. In FSD, the rate of negative margins decreased and that of borderline and positive margins increased according to the extent of the remaining epithelium. Diagnostic discordance between FSD and PSD was observed in 31 epithelial layers and two subepithelial layers. Alteration from borderline to negative was the most frequent(20 of the 31 epithelial layers). Patients with positive margin in the total and epithelial layers by FSD demonstrated a significantly worse local recurrence-free survival(RFS) compared with patients with borderline and negative margins, which revealed comparable local RFS. Patients with borderline and negative margins in the epithelial layer by PSD also revealed comparable local RFS. These results suggested that epithelial borderline might be regarded substantially as negative. When classifying the status of the epithelial layer either as negative or positive, concordance rates between FSD and PSD in the total, epithelial, and subepithelial layers were 95.0%, 93.0%, and 98.0%, respectively.CONCLUSION During intraoperative assessment of bile duct margin, borderline in the epithelial layer can be substantially regarded as negative, under which condition FSD is comparable to PSD.
基金supported by the Ministry of Education Chunhui Program Collaborative Scientific Research Projects(Grant No.:HZKY20220286)Henan Province Foreign Experts Introduction Program(Grant No.:HNGD2022021)+1 种基金Natural Science Foundation of Henan Province(Grant No.:23230042151)the Foundation of the National Key Program of Research and Development of China(Grant No.:2016YFC0900803)。
文摘Rapid population aging has led to an increased focus on age-related conditions such as sarcopenia.causing loss of muscle mass and strength^([1,2]). Sarcopenia is associated with adverse outcomes,including falls, functional decline, frailty, and mortality, which can lower the quality of life and shorten lifespan^([1,2]).
文摘Dear Editor,I am writing in response to the article“Assessment of nurses’workplace silence behavior motives:A cross-sectional study”by Alhojairi et al.published in the September 2024 issue of the International Journal of Nursing Sciences[1].This is a letter written by a nurse with 10 years of clinical work experience and a personal interest in team dynamics.I appreciate the authors'recommendations on mitigating workplace silence among nurses to enhance clinical work development,and I believe their proposals could be expanded further.
文摘BACKGROUND Oil-based iodinated contrast media have excellent contrast properties and are widely used for hysterosalpingographic evaluation of female infertility.On abdominal radiography and computed tomography(CT)scans,their radiodensity is similar to that of metallic objects,which can sometimes lead to diagnostic confusion in the postoperative settings.In this case,retained oil-based contrast medium was observed on an abdominal radiograph following a cesarean section,making it difficult to differentiate from an intraperitoneal foreign body from surgery.The patient was a 37-year-old pregnant woman who was referred to our hospital at 32 weeks and 1 day of pregnancy due to complete placenta previa for mana-gement of pregnancy and delivery.An elective cesarean section was performed at 37 weeks and 3 days.A plain abdominal radiograph taken immediately after surgery revealed a near-round,hyperdense,mass-like shadow with a regular margin in the pelvic cavity.An intraperitoneal foreign body was suspected;therefore,an abdominal CT scan was performed.The foreign body was located on the left side of the pouch of Douglas and had a CT value of 7000 Hounsfield units,similar to that of metals.The CT value strongly suggested the presence of an artificial object.However,further inquiries with the patient and her previous physician revealed a history of hysterosalpingography.Accordingly,retained oil-based iodinated contrast medium was suspected,and observation of the object’s course was adopted.CONCLUSION When intraperitoneal foreign bodies are suspected on postoperative radiographs,the possibility of oil-based iodinated contrast medium retention should be considered.
文摘(此课选自义务教育课程标准实验教科书《英语》(新目标)Go for it.九年级(全一册))一、设计理念:本节课的教学内容是一节完整的阅读板块,采用单词讲解,读前预测,读中利用寻读和细读的阅读策略提取文章关键信息,读后利用思维导图总结全文信息,然后讲解文章难句的设计思路,培养学生的分析能力和阅读技能。
文摘BACKGROUND Intrathecal bupivacaine is the traditional anesthetic drug used in spinal anesthesia for caesarean sections(CSs),but ropivacaine has emerged as a potential alter-native.This meta-analysis compares the efficacy and safety of intrathecal hyper-baric bupivacaine vs hyperbaric ropivacaine for cesarean sections.AIM To systematically evaluate and compare the efficacy and safety of intrathecal hyperbaric bupivacaine and hyperbaric ropivacaine for spinal anesthesia in CSs.METHODS A thorough search of electronic databases was carried out to find pertinent randomized controlled trials(RCTs)comparing intrathecal hyperbaric ropi-vacaine and hyperbaric bupivacaine during CSs.PubMed,Cochrane database,Google Scholar,and Scopus were searched,and papers from January 2000 to January 2024 were deemed eligible and filtered using predetermined inclusion and exclusion criteria.Studies were assessed for methodological quality,and data were extracted for time to adequate anesthesia(sensory and motor blockade),duration of sensory and motor block,hemodynamic changes and side effect profile.The standardized mean difference with 95%CI was used for continuous data.Dichotomous variables were assessed using the Mantel-Haenszel test and the random effect model to compute the odds ratio.RESULTS Total 8 RCTs were selected from a pool of 119 search results for meta-analysis.The meta-analysis evaluated pooled effect sizes and assessed heterogeneity among the studies.The primary objective was to compare key outcomes to identify any significant variances in efficacy and safety profiles between two local anesthetics.The analysis revealed that the difference in the onset of sensory blockade between the two local anesthetics was statistically insignificant(P=0.1586).However,the onset of motor blockade appeared to be faster with bupivacaine(P=0.03589).Additionally,the regression of sensory and motor blockade occurred earlier in the ropivacaine group.Furthermore,the duration of the first analgesic effect was shorter with a significance level of P<0.05.Regarding side effects profile,including hypotension,nausea,and shivering,the study did not observe any significant differences between the two groups.CONCLUSION This meta-analysis offers insights into the effectiveness and safety of hyperbaric bupivacaine vs ropivacaine for cesarean sections.Hyperbaric ropivacaine had a comparable safety profile and faster regression of sensory and motor blockade than hyperbaric bupivacaine,perhaps aiding early mobilization of parturient and facilitating mother-child bonding.Choosing ropivacaine may offer benefits beyond efficacy for cesarean section patients and short surgical procedures.
基金National Natural Science Foundation of China under Grant Nos.52078205 and 42172322Joint Fund for High-Speed Railway Basic Research under Grant No.U2268213the Postgraduate Scientific Research Innovation Project of Hunan Province under Grant Nos.QL20230104 and CX20240431。
文摘Foamed concrete is widely employed in highway transition sections,due to its lightweight,high-strength,and effective settlement control.It is crucial to investigate its dynamic response linked to the traffic-loading influence zone of embankment and transition section smoothness.In this study,in-situ truck tests were conducted in the road-culvert-bridge transition section to obtain the spatio-temporal response patterns.Based on the vertical response,the influence zone was ascertained.Depending on the longitudinal response,the smoothness was evaluated by equivalent dynamic stiffness(EDS)and acceleration variation rate(AVR).Furthermore,the response discrepancies of embankments with different fillings were compared.Findings reveal exponential attenuation of dynamic stress and acceleration with increasing depth.The acceleration and dynamic displacement exhibit U-shaped patterns in the culvert subsection and abrupt changes in the bridgehead subsection.The influence zone determined by the acceleration attenuation coefficient method,dynamic stress attenuation method,and stress diffusion angle method was 1.55 m,2.05 m,and 2.89 m,respectively.The maximum disparity in EDS occurs at the culvert subsection and bridge abutment,and the AVR ranges from 0 to 0.52 s^(-2).Moreover,94.1%attenuation of the dynamic stress occurred within the 1.5-meter foamed concrete embankment under the setting of 100 kN-60 km/h.
文摘Aspects of the general Vlasov theory are examined separately as applied to a thin-walled channel section cantilever beam under free-end end loading. In particular, the flexural bending and shear that arise under transverse shear and axial torsional loading are each considered theoretically. These analyses involve the location of the shear centre at which transverse shear forces when applied do not produce torsion. This centre, when taken to be coincident with the centre of twist implies an equivalent reciprocal behaviour. That is, an axial torsion applied concentric with the shear centre will twist but not bend the beam. The respective bending and shear stress conversions are derived for each action applied to three aluminium alloy extruded channel sections mounted as cantilevers with a horizontal principal axis of symmetry. Bending and shear are considered more generally for other thin-walled sections when the transverse loading axes at the shear centre are not parallel to the section = s centroidal axes of principal second moments of area. The fixing at one end of the cantilever modifies the St Venant free angular twist and the free warping displacement. It is shown from the Wagner-Kappus torsion theory how the end constrained warping generates an axial stress distribution that varies with the length and across the cross-section for an axial torsion applied to the shear centre. It should be mentioned here for wider applications and validation of the Vlasov theory that attendant papers are to consider in detail bending and torsional loadings applied to other axes through each of the centroid and the web centre. Therein, both bending and twisting arise from transverse shear and axial torsion applied to each position being displaced from the shear centre. Here, the influence of the axis position upon the net axial and shear stress distributions is to be established. That is, the net axial stress from axial torsional loading is identified with the sum of axial stress due to bending and axial stress arising from constrained warping displacements at the fixing. The net shear stress distribution overlays the distributions from axial torsion and that from flexural shear under transverse loading. Both arise when transverse forces are displaced from the shear centre.
文摘BACKGROUND Transition is a critical period for adolescents as they begin to assume responsibility for their own health.Similarly,the shift from pediatric to adult healthcare represents a vulnerable phase,marked by unique challenges in adolescent health care.Despite its importance,only a few studies have explored healthcare transition among adolescents in Uganda.AIM To identify factors associated with the transition to adult human immunodeficiency virus(HIV)-centered care among adolescents attending HIV/AIDS clinics in Uganda.METHODS A cross-sectional mixed-methods study was conducted among 265 adolescents,randomly selected from three antiretroviral therapy(ART)clinics,using a structured questionnaire.Focus group discussions and key informant interviews were conducted.Individuals aged 10-20 years who were actively enrolled in the ART program between January 4,2022 and January 30,2023 were recruited.The primary outcome of interest was the transition to adult care.Bivariate and multivariate analyses were performed for quantitative data,while content analysis was used to analyze qualitative data.RESULTS The prevalence of transition to adult care was 40.6%.Most participants were male(53.6%)and fell within the 13-15 age group(35.6%).Multivariate logistic regression analysis identified several factors significantly associated with transition to adult care:Age group 10-12 years[prevalence ratio(PR)=2.525,95%CI:2.121-2.944,P=0.002],Age group 13-15 years(PR=1.900,95%CI:1.196-3.416,P=0.001),successful viral load suppression(PR=1.534,95%CI:1.173-1.648,P=0.016),disclosure of HIV status to relatives(PR=5.001,95%CI:3.411-3.611,P=0.000),being prepared for transitioning(PR=5.417,95%CI:3.468-7.135,P=0.041)and having skilled pediatric caregivers(PR=3.724,95%CI:2.084-4.105,P=0.005).CONCLUSION Transition to adult care among adolescents was low.Improving transition outcomes may require strengthening individual support within the family context and integrating transition-focused care into existing specialized clinical settings to enhance the delivery of adolescent-friendly services.
基金supported by the National Natural Science Foundation of China(Nos.12465024,12365018,U2032146)Inner Mongolia National Science Foundation(Nos.2024ZD23,2024FX30,2023MS01005)+1 种基金Program for Innovative Research Team in Universities of Inner Mongolia Autonomous Region(NMGIRT2217)Program for Young Talents of Science and Technology in Universities of Inner Mongolia Autonomous Region(NJYT23109)。
文摘The neutron capture cross section for^(165)Ho was measured at the backstreaming white neutron beam line(Back-n)of the China Spallation Neutron Source(CSNS)using total energy detection systems,composed of a set of four C_(6)D_(6)scintillator detectors coupled with pulse height weighting techniques.The resonance parameters were extracted using the multilevel multichannel R-matrix code SAMMY to fit the measured capture yields of the^(165)Ho(n,γ)reaction in the neutron energy range below100 eV.Subsequently,the resonance region’s capture cross sections were reconstructed based on the obtained parameters.Furthermore,the unresolved resonance average cross section of the^(165)Ho(n,γ)reaction was determined relative to that of the standard sample^(197)Au within the neutron energy range of 2 keV to 1 MeV.The experimental data were compared with the recommended nuclear data from the ENDF/B-VIII.0 library,as well as with results of calculations performed using the TALYS-1.9 code.The comparison revealed agreement between the measured^(165)Ho(n,γ)cross sections and these data.The present results are crucial for evaluating the^(165)Ho neutron capture cross section and thus enhance the quality of evaluated nuclear data libraries.They provide valuable guidance for nuclear theoretical models and nuclear astrophysical studies.
基金financially supported by the National Natural Science Foundation of China(Grant No.11372136)
文摘Analyzing the mass of behind-armor debris (BAD) generated by Rolled Homogeneous Armor (RHA) subjected to normal penetration of variable cross-section Explosively Formed Projectile (EFP) is the purpose of this paper. So theoretical analysis, numerical simulation and experimental data are combined to analyze the influence of variable cross-section characteristic on the time history of crater radius. Moreover the relationships between time history of crater radius (as well as mass of BAD) and the thickness of RHA (from 30mm to 70 mm) and the impact velocity of EFP (1650 m/s to 1860 m/s) are also investigated. The results indicate that: 1) being compared to the variable cross-section characteristic is ignored, the theoretical time history of crater radius is in better agreement with the simulation results when the variable cross-section characteristic is considered;2) being compared to the other three conditions of plug, the theoretical mass of BAD is in the best agreement with the simulation results when the shape of plug is frustum of a cone and the angle between generatrix and bottom is 45- and the axial length of mushroom is considered.
文摘The identification and characterization of rock types is a core activity in geology and related fields,including mining,petroleum,environmental science,industry,and construction.Traditionally,this task is performed by human specialists who analyze and describe the type,composition,texture,shape,and other properties of rock samples,whether collected in-situ or prepared in a laboratory.However,the process is subjective,dependent on the specialist’s experience,and time-consuming.This study proposes an artificial intelligence-based approach that combines computer vision and natural language processing to generate both textual and verbal descriptions from images of rock thin sections.A dataset of images and corresponding textual descriptions is used to train a hybrid deep learning model.Features extracted from the images using EfficientNetB7 are processed by a Transformer network to generate textual descriptions,which are then converted into verbal responses using a speech synthesis service.The experimental results show an accuracy of 0.892 and a BLEU score of 0.71.This model offers potential utility for research,professional,and academic applications and has been deployed as a web application for public use.
文摘Objective:The objective of this study is to determine the effect of nurse-led instructional video(NLIV)on anxiety,satisfaction,and recovery among mothers admitted for cesarean section(CS).Materials and Methods:A quasi-experimental design was carried out on the mothers scheduled for CS.Eighty participants were selected by a purposive sampling technique,which were divided(40 participants in each group)into an experimental group and a control group.Nurse-led informational video(NLIV)was shown to the experimental group,and routine care was provided for the control group.Modified hospital anxiety scale(HADS),scale for measuring maternal satisfaction in cesarean birth,and obstetric quality of recovery following cesarean delivery were used to assess anxiety,satisfaction,and recovery.Results:Both the experimental and control groups showed significant reductions in anxiety by the first postintervention day(P<0.001),with the experimental group experiencing a greater mean reduction(mean difference[MD]=4.37)than the control group(MD=3.35)but the intergroup difference was not statistically significant(P>0.05).The experimental group reported significantly higher satisfaction scores(175.55±9.42)on the 3rd postoperative day compared to the control group(151.93±14.89;P<0.001).Similarly,the experimental group’s recovery scores(79.90±6.24)were considerably higher than those of the control group(62.45±15.18;P<0.001).On the 3rd postintervention day,satisfaction was significantly associated with age(P<0.001),and recovery with gravidity(P<0.05).Conclusions:NLIV can be used in the preoperative period to reduce anxiety related to CS and to improve satisfaction and recovery after the CS.
文摘Emergency cesarean section has always been a challenge for patients,surgeons,and anesthesiologists,as it endangers the safety of both parturients and fetuses.Obesity and hypertension are common among pregnant women,but severe obesity combined with refractory hypertension is very rare in clinical practice.The optimal anesthetic management strategy for obese pregnant women with a difficult airway and poorly controlled hypertension remains debatable.This report presents a 32-year-old woman with severe obesity and refractory hypertension at 36 weeks and 6 days of pregnancy.Owing to fetal heart rate abnormalities,she was scheduled for emergency cesarean section.Given the urgency of the fetal condition and the challenges posed by the patient's obesity for epidural puncture,the anesthesiologist opted for rapid sequence induction and tracheal intubation instead of intervertebral anesthesia.Short-acting antihypertensive medications were adminstrated preoperatively to control elevated blood pressure,and vasopressor agents were continuously infused during surgery to prevent severe hypotension induced by anesthetic drugs.The entire anesthesia and surgical procedure proceeded uneventfully,with no major adverse events observed.Both the patient and fetus achieved favorable outcomes.This case indicates that early anesthetic risk assessment and meticulous pre-delivery planning are paramount,necessitating personalized management of airway and hemodynamics to optimize outcomes in obese parturients.
基金supported by the National Natural Science Foundation of China under Grant No.62271043Ministry of Education of China under Grant No.8091B032123Beijing Natural Science Foundation under Grant No.L212029。
文摘Radar cross section(RCS)plays a critical role in modeling target scattering characteristics and enhancing the precision of target detection and localization in integrated sensing and communication(ISAC)systems.This paper investigates the human body RCS at 26 GHz via multiangle channel measurements under different clothing conditions.Based on calibrated electromagnetic(EM)parameters,the RCS characteristics of the human body in far-field conditions are analyzed using ray-tracing(RT)simulations.Some suggestions for the design of ISAC systems are also discussed.The results provide a solid theoretical foundation and practical reference for the modeling of target scattering characteristics for ISAC channels.
基金The National Natural Science Foundation of China(No.52338011,52378291)Young Elite Scientists Sponsorship Program by CAST(No.2022-2024QNRC0101).
文摘To overcome the limitations of low efficiency and reliance on manual processes in the measurement of geometric parameters for bridge prefabricated components,a method based on deep learning and computer vision is developed to identify the geometric parameters.The study utilizes a common precast element for highway bridges as the research subject.First,edge feature points of the bridge component section are extracted from images of the precast component cross-sections by combining the Canny operator with mathematical morphology.Subsequently,a deep learning model is developed to identify the geometric parameters of the precast components using the extracted edge coordinates from the images as input and the predefined control parameters of the bridge section as output.A dataset is generated by varying the control parameters and noise levels for model training.Finally,field measurements are conducted to validate the accuracy of the developed method.The results indicate that the developed method effectively identifies the geometric parameters of bridge precast components,with an error rate maintained within 5%.
基金supported by the National Key Research and Development Plan(No.2016YFA0401603)the National Natural Science Foundation of China(No.11675155)
文摘To verify the performance of the neutron total cross-sectional spectrometer, the neutron total cross section of carbon is initially measured in the energy range of 1 eV to 20 MeV using the time-of-flight method. The measurement is performed at the Back-n white neutron source with a 76-m time-of-flight path using the China Spallation Neutron Source. A multilayer fast fission chamber with 235U and 238U is employed as the neutron detector. The diameter and thickness of the natural graphite sample are 70 mm and 40 mm, respectively. Signal waveforms are collected using a data acquisition system. Off-line data processing was used to obtain the neutron time-of-flight spectra and transmissions. The uncertainty of the counting statistics is generally approximately 3% for each bin in the energy range of 1–20 MeV. It is determined that the results for the neutron total cross section of carbon obtained using ^235U cells are in good agreement with the results obtained using 238U cells within limits of statistical uncertainty. Moreover, the measured total cross sections show good agreement with the broadening evaluated data.
