In the past 20 years, great progress has been achieved in China in the construction of concrete-filled steel tube （CFST） arch bridges and concrete arch bridges with a CFST skeleton. The span of these bridges has bee...In the past 20 years, great progress has been achieved in China in the construction of concrete-filled steel tube （CFST） arch bridges and concrete arch bridges with a CFST skeleton. The span of these bridges has been increasing rapidly, which is rare in the history of bridge development. The large-scale construction of expressways and high-speed railways demands the development of long-span arch bridges, and advances in design and construction techniques have made it possible to construct such bridges. In the present study, the current status, development, and major innovative technologies of CFST arch bridges and concrete arch bridges with a CFST skeleton in China are elaborated. This paper covers the key con- struction technologies of CFST arch bridges, such as the design, manufacture, and installation of steel tube arch trusses, the preparation and pouring of in-tube concrete, and the construction of the world＇s longest CFST arch bridge-the First Hejiang Yangtze River Bridge. The main construction technologies of rein- forced concrete arch bridges are also presented, which include cable-stayed fastening-hanging cantilever assembly, adjusting the load by means of stay cables, surrounding the concrete for arch rib pouring, and so forth. In addition, the construction of two CFST skeleton concrete arch bridges-the Guangxi Yongning Yong River Bridge and the Yunnan-Guangxi Railway Nanpan River Bridge--is discussed. CFST arch bridges in China have already gained a world-leading position; with the continuous innovation of key technologies, China will become the new leader in promoting the development of arch bridges.展开更多
Because China is becoming an aging society,the incidence of diabetes and diabetic foot have been increasing.Diabetic foot has become one of the main health-related killers due to its high disability and mortality rate...Because China is becoming an aging society,the incidence of diabetes and diabetic foot have been increasing.Diabetic foot has become one of the main health-related killers due to its high disability and mortality rates.Negative pressure wound therapy(NPWT)is one of the most effective techniques for the treatment of diabetic foot wounds and great progress,both in terms of research and its clinical application,has been made in the last 20 years of its development.However,due to the complex pathogenesis and management of diabetic foot,irregular application of NPWT often leads to complications,such as infection,bleeding and necrosis,that seriously affect its treatment outcomes.In 2020,under the leadership of Burns,Trauma and Tissue Repair Committee of the Cross-Straits Medicine Exchange Association,the writing group for‘Consensus on the application of negative pressure wound therapy of diabetic foot wounds’was established with the participation of scholars from the specialized areas of burns,endocrinology,vascular surgery,orthopedics and wound repair.Drawing on evidence-based practice suggested by the latest clinical research,this consensus proposes the best clinical practice guidelines for the application and prognostic evaluation of NPWT for diabetic foot.The consensus aims to support the formation of standardized treatment schemes that clinicians can refer to when treating cases of diabetic foot.展开更多
Objective To explore the influence factors in hematoma formation after removing benign breast lesions with an ultrasound-guided vacuum-assisted system.Methods A total of 232 females with 312 benign breast masses recei...Objective To explore the influence factors in hematoma formation after removing benign breast lesions with an ultrasound-guided vacuum-assisted system.Methods A total of 232 females with 312 benign breast masses received excisional biopsy with ultrasoundguided vacuum-assisted system.The pathology of patients,results of hematoma development and outcome,influence factors for hematoma occurrence(nodule size,nodule location,number of nodule,breast shape,menstrual period,efficacy time of bandage,and application of hemostatic agents during the procedure) were recorded.Results Pathologic examination revealed fibroadenomas in 138 lesions,fibroadenosis in 127 lesions,intraductal papillomas in 39 lesions,inflammatory change in 4 lesions,retention cyst of the breast in 3 lesions,and benign phyllodes tumor in 1 lesion.Thirty hematomas were observed in patients(9.6%).Finally,97.0%hematomas were absorbed completely within 6 months follow-up.The incidence rates of hematoma were increased by 24.7%,10.0%,63.2%,13.9%in the nodule diameter larger or equal to 25 mm group,removal of larger or equal to two nodules once time from one patient group,menstrual period group,and larger and loose breast group,respectively(all P<0.05).However,the incidences were decreased by 60.6%in the bandage performed for 12-24 hours or beyond 24 hours group(P<0.05).The multiple logistic regression models revealed that nodule size(x^2=15.227,P<0.001),number of nodule(x^2=7.767,P=0.005),menstrual period(x^2=24.530,P<0.001),and breast shape(x^2=9.559,P=0.002) were independent risk factors associated with hematoma occurrence,but efficacy time of bandage was a protective factor associated with hematoma occurrence.Conclusion The occurrence of hematoma after the minimally invasive operation was associated with nodule size,number of nodule,menstrual period,breast shape,and efficacy time of bandage.展开更多
The structures in vacuum-assist high-pressure die casting （HPDC） AM60B alloy were studied by using an optical microscope and a scanning electron microscope with an energy dispersive spectrometer. It was found that t...The structures in vacuum-assist high-pressure die casting （HPDC） AM60B alloy were studied by using an optical microscope and a scanning electron microscope with an energy dispersive spectrometer. It was found that the HPDC under the vacuum could significantly change the morphology and distribution of the microstructure. For both conventional and vacuum-assist HPDC processes, the externally solidified crystals （ESCs） tended to aggregate in the center along the thickness direction of the castings. Besides, the aggregation was more pronounced, and the number of ESCs decreased, and the ESCs tended to become smaller and more globular, as the distance between the specimen location and runner increased. Compared with the conventional castings, the vacuum-assist HPDC can significantly reduce the size and amount of ESCs, and the ESCs tended to be more globular. For the distribution of ESCs along the thickness of the specimens, the aggregation tendency was more pronounced in vacuum-assist die castings than that in conventional castings. Besides, the distribution of ESCs at different locations was more converged in the vacuum-assist HPDC than that in the conventional HPDC.展开更多
There is increasing concern about the safety of homologous blood transfusion during cardiac surgery,and a restrictive transfusion practice is associated with improved outcome.Transfusion-free pediatric cardiac surgery...There is increasing concern about the safety of homologous blood transfusion during cardiac surgery,and a restrictive transfusion practice is associated with improved outcome.Transfusion-free pediatric cardiac surgery is unrealistic for the vast majority of procedures in neonates or small infants;however,considerable progress has been made by using techniques that decrease the need for homologous blood products or even allow bloodless surgery in older infants and children.These techniques involve a decrease in prime volume by downsizing the bypass circuit with the help of vacuumassisted venous drainage,microplegia,autologous blood predonation with or without infusion of recombinant(erythropoietin),cell salvaging,ultrafiltration and retrograde autologous priming.The three major techniques which are simple,safe,efficient,and cost-effective are:a prime volume as small as possible,cardioplegia with negligible hydric balance and circuit residual blood salvaged without any alteration.Furthermore,these three techniques can be used for all the patients,including emergencies and small babies.In every pediatric surgical unit,a strategy to decrease or avoid blood bank transfusion must be implemented.A strategy to minimize transfusion requirement requires a combined effort involving the entire surgical team with pre-,peri-,and postoperative planning and management.展开更多
Some precision electronics such as signal transmitters need to not only emit effective signal but also be protected from the external electromagnetic(EM)waves.Thus,directional electromagnetic interference(EMI)shieldin...Some precision electronics such as signal transmitters need to not only emit effective signal but also be protected from the external electromagnetic(EM)waves.Thus,directional electromagnetic interference(EMI)shielding materials(i.e.,when the EM wave is incident from different sides of the sample,the EMI shielding effectiveness(SE)is rather different)are strongly required;unfortunately,no comprehensive literature report is available on this research field.Herein,Nicoated melamine foams(Ni@MF)were obtained by a facile electroless plating process,and multiwalled carbon nanotube(CNT)papers were prepared via a simple vacuum-assisted self-assembly approach.Then,step-wise asymmetric poly(butylene adipate-co-terephthalate)(PBAT)composites consisting of loose Ni@MF layer and compact CNT layer were successfully fabricated via a facile solution encapsulation approach.The step-wise asymmetric structures and electrical conductivity endow the Ni@MF/CNT/PBAT composites with unprecedented directional EMI shielding performances.When the EM wave is incident from Ni@MF layer or CNT layer,Ni@MF-5/CNT-75/PBAT exhibits the total EMI SE(SET)of 38.3 and 29.5 dB,respectively,which illustrates theΔSET of 8.8 dB.This work opens a new research window for directional EMI shielding composites with step-wise asymmetric structures,which has promising applications in portable electronics and next-generation communication technologies.展开更多
To editor:Shoulder dystocia(SD)constitutes an obstetric emergency,bearing associations with maternal and neonatal morbidity due to its unique pathophysiology.In a comprehensive series involving 228,438 women,SD occurr...To editor:Shoulder dystocia(SD)constitutes an obstetric emergency,bearing associations with maternal and neonatal morbidity due to its unique pathophysiology.In a comprehensive series involving 228,438 women,SD occurred in 2159 patients,accounting for 1.7%of the total.1 Various techniques have been described to facilitate successful delivery in SD patients;2 however,these maneuvers are not without associated complications.3 This correspondence highlights a case of a newborn experiencing a collapse following such a delivery.The guardian granted written and informed consent for the publication of the patient’s clinical information and associated images.展开更多
Diamond/aluminium composites have attracted attention in the field of thermal management of electronic packaging for their excellent properties.In order to solve the interfacial problem between diamond and aluminium,a...Diamond/aluminium composites have attracted attention in the field of thermal management of electronic packaging for their excellent properties.In order to solve the interfacial problem between diamond and aluminium,a novel process combining pressure infiltration with vacuum-assisted technology was proposed to prepare diamond/aluminum composites.The effect of diamond particle size on the microstructure and properties of the diamond/Al-12Si composites was investigated.The results show that the diamond/Al-12Si composites exhibit high relative density and a uniform microstructure.Both thermal conductivity and coefficient of thermal expansion increase with increasing particle size,while the bending strength exhibits the opposite trend.When the average diamond particle size increases from 45μm to 425μm,the thermal conductivity of the composites increases from 455 W·m^(-1)·K^(-1)to 713 W·m^(-1)·K^(-1)and the coefficient of thermal expansion increases from 4.97×10^(-6)K^(-1)to 6.72×10^(-6)K^(-1),while the bending strength decreases from 353 MPa to 246 MPa.This research demonstrates that high-quality composites can be prepared by the vacuum-assisted pressure infiltration process and the thermal conductivity of the composites can be effectively improved by increasing the diamond particle size.展开更多
BACKGROUND The diabetic foot is a common cause of disability and death,and comorbid foot infections usually lead to prolonged hospitalization,high healthcare costs,and a significant increase in amputation rates.And mo...BACKGROUND The diabetic foot is a common cause of disability and death,and comorbid foot infections usually lead to prolonged hospitalization,high healthcare costs,and a significant increase in amputation rates.And most diabetic foot trauma is complicated by lower extremity arteriopathy,which becomes an independent risk factor for major amputation in diabetic foot patients.AIM To establish the efficacy and safety of endovascular revascularization(ER)combined with vacuum-assisted closure(VAC)for the treatment of diabetic foot.METHODS Clinical data were collected from 40 patients with diabetic foot admitted to the Second Affiliated Hospital of Soochow University from April 2018 to April 2022.Diabetic foot lesions were graded according to Wagner’s classification,and blood flow to the lower extremity was evaluated using the ankle-brachial index test and computerized tomography angiography of the lower extremity arteries.Continuous subcutaneous insulin infusion pumps were used to achieve glycemic control.Lower limb revascularization was facilitated by percutaneous transluminal balloon angioplasty(BA)or stenting.Wounds were cleaned by nibbling debridement.Wound granulation tissue growth was induced by VAC,and wound repair was performed by skin grafting or skin flap transplantation.RESULTS Of the 35 cases treated with lower limb revascularization,34 were successful with a revascularization success rate of 97%.Of these,6 cases underwent stenting after BA of the superficial femoral artery,and 1 received popliteal artery stent implantation.In the 25 cases treated with infrapopliteal artery revascularization,39 arteries were reconstructed,7 of which were treated by drug-coated BA and the remaining 32 with plain old BA.VAC was performed in 32 wounds.Twenty-four cases of skin grafting and 2 cases of skin flap transplantation were performed.Two patients underwent major amputations,whereas 17 had minor amputations,accounting for a success limb salvage rate of 95%.CONCLUSION ER in combination with VAC is a safe and effective t展开更多
Axillary lymph node status is one of the most important prognostic indicator of survival for breast cancer, especially in ductal carcinoma in situ （DCIS）. The purpose of this study was to investigate whether sentine...Axillary lymph node status is one of the most important prognostic indicator of survival for breast cancer, especially in ductal carcinoma in situ （DCIS）. The purpose of this study was to investigate whether sentinel lymph node biopsy （SLNB） should be performed in patients with an initial diagnosis of DCIS. Methods： A retrospective study was performed of 124 patients with an initial diagnosis of DCIS between March 2000 and June 2014. The patients were treated with either SLNB or axillary node dissection during the surgery, and we compared the clinicopathologic characteristics, image features, and immunohistochemical results. Results： Eighty-two patients （66.1%） had pure DCIS and 25 （20.2%） had DCIS with microinvasion （DCISM）, 17 （13.7%） updated to invasive breast cancer （IBC）. 115 patients （92.7%） underwent SLNB, among them, 70 patients （56.5%） underwent axillary node dissection. 3 of 115 patients （2.6%） had a positive sentinel lymph node, only 1 （1.4%） of 70 patients had axillary lymph node metastasis, in 84 patients （66.7%） who were diagnosed DCIS by core needle biopsy （CNB） and vacuum-assisted biopsy （VAB）. 26 patients （31.0%） were upstaged into IBC or DCISM in the final histological diagnosis. The statistically significant factors predictive of underestimation were large tumor size, microcalcifications, comedo necrosis, positive Her-2 status, negative estrogen receptor status. Conclusion： The metastasis of sentinel lymph nodes in pure DCIS is very low, but the underestimation of invasive carcinoma in patients with an initial diagnosis of DCIS is an usual incident, especially in the cases when DCIS is diagnosed by CNB or VAB. Our findings suggest patients presenting with a preoperative diagnosis of DCIS associated with large tumor sizes, microcalcifications, comedo necrosis, positive Her-2 status, negative ER status are more likely to be DCISM and IBC in final diagnosis. SLNB should be performed in this part of patients.展开更多
BACKGROUND Ductal carcinoma in situ(DCIS)arising within fibroadenoma is a type of tumor that is rarely encountered in clinic,with only about 100 cases of carcinoma arising within a fibroadenoma reported in the literat...BACKGROUND Ductal carcinoma in situ(DCIS)arising within fibroadenoma is a type of tumor that is rarely encountered in clinic,with only about 100 cases of carcinoma arising within a fibroadenoma reported in the literature.Here,we present two cases of breast DCIS arising within a fibroadenoma and discuss their clinical and imaging findings as well as treatment.CASE SUMMARY The patients did not have cancer-related personal and family histories.Case 1(a 49-year-old woman)was diagnosed with a bilateral breast nodule in May 2018 and was followed(preoperative imaging data including ultrasound and mammography)for 3 years;she underwent an excisional biopsy to address an enlargement in nodule size.Case 2(a 37-year-old woman)was diagnosed with a left breast nodule in June 2021 and consequently received vacuum-assisted biopsy of the tumor which appeared as“irregularly shaped”and“unevenly textured”tissue on ultrasound.The pathological diagnosis was clear in both cases.Both patients underwent breast-conserving surgery and sentinel lymph node biopsy.The two cases received or planned to receive radiotherapy as well as endocrine therapy(tamoxifen).CONCLUSION Breast DCIS arising within a fibroadenoma is rare,but patients treated with radiotherapy and endocrine therapy can have good prognosis.展开更多
The demand for lightweight, flexible, and high-performance portable power sources urgently requires high-efficiency and stable flexible solar cells. In the case of perovskite solar cells(PSCs), most of the common elec...The demand for lightweight, flexible, and high-performance portable power sources urgently requires high-efficiency and stable flexible solar cells. In the case of perovskite solar cells(PSCs), most of the common electron transport layer(ETL) needs to be annealed for improving the optoelectronic properties,while conventional flexible substrates could barely stand the high temperature. Herein, a vacuumassisted annealing SnO_(2) ETL at low temperature(100℃) is utilized in flexible PSCs and achieved high efficiency of 20.14%. Meanwhile, the open-circuit voltage(V_(oc)) increases from 1.07 V to 1.14 V. The flexible PSCs also show robust bending stability with 86.8% of the initial efficiency is retained after 1000 bending cycles at a bending radius of 5 mm. X-ray photoelectron spectroscopy(XPS), atomic force microscopy(AFM), and contact angle measurements show that the density of oxygen vacancies, the surface roughness of the SnO_(2) layer, and film hydrophobicity are significantly increased, respectively. These improvements could be due to the oxygen-deficient environment in a vacuum chamber, and the rapid evaporation of solvents. The proposed vacuum-assisted low-temperature annealing method not only improves the efficiency of flexible PSCs but is also compatible and promising in the large-scale commercialization of flexible PSCs.展开更多
Background: Deep sternal wound infection (DSWI), or mediastinitis, is a devastating complication of coronary artery bypass grafting (CABG). This prospective study aimed to assess our management of DSWI in view of the ...Background: Deep sternal wound infection (DSWI), or mediastinitis, is a devastating complication of coronary artery bypass grafting (CABG). This prospective study aimed to assess our management of DSWI in view of the published literature. Methods: Over 2-years (ending in January 2016), 29 patients (20 males) developed DSWI amongst 520 patients who underwent standard CABG surgeries (5.6%). Pre-, intra- and postoperative variables were documented. Whenever possible, the infections were culture-verified. Besides antibiotics, patients received one or more of the following therapies: drainage, debridement, closed irrigation, sternal re-wiring, vacuum-assisted closure (VAC), and bone resection. Results: the male to female ratio was 2.2:1. Mean age was 58.1 ± 7.3 years. The mean body mass index (BMI) was 27.9 ± 3.4 kg/m<sup>2</sup>. There were 18, 16 and 11 patients with diabetes mellitus (DM), hypertension and chronic obstructive pulmonary disease (COPD) respectively. Cardiopulmonary bypass (CPB) was utilized in 26 (89.7%) patients with a mean time of 117.5 ± 23.3 minutes. Most surgeries (n = 21, 72.4%) lasted 5 - 6 hrs. According to Pairolero classification, there were 3 (10.3%) Type I, 22 (75.9%) Type II and 4 (13.8%) Type III infections. Four (13.8%) cases were culture-verified. Twenty-three (79.3%) DSWIs were surgically managed. Sternal re-wiring was performed in 14 (48.3%) cases while VAC was added to other therapies in 2 (6.9%) patients. DSWIs completely resolved in 18 (62.0%) patients within 3 - 24 weeks while two (6.9%) patients died within 30 days. Conclusion: We have identified six independent risk factors for DSWI (male gender, obesity, DM, hypertension, COPD and CPB), five of them are modifiable.展开更多
Vacuum-assisted breast biopsy (VABB) plays a fundamental role in the preoperative assessment of breast lesions pro- viding large histology samples that are useful to define diagnoses and biological parameters to guide...Vacuum-assisted breast biopsy (VABB) plays a fundamental role in the preoperative assessment of breast lesions pro- viding large histology samples that are useful to define diagnoses and biological parameters to guide treatment planning. This technique has been used in our institute since 2000 and two new wireless handheld ultrasound-guided VABB de- vices have been introduced since May 2012. In this report we analyze our experience with these revolutionary devices which are able to provide the option of single-insertion contiguous tissue samples respectively with a 13/14-gauge aperture. Our initial experience on 75 lesions shows that these devices are safe, fast, procedurally advantageous for operators and well accepted by patients. Finally VABB procedures can markedly reduce the need for surgical biopsy.展开更多
基金supported by the Fund for Young Scientists of Sichuan University, China (2011SCU11081)Research Fund for the Doctoral Program of Higher Education, Ministry of Education of China (20120181120103)~~
文摘In the past 20 years, great progress has been achieved in China in the construction of concrete-filled steel tube （CFST） arch bridges and concrete arch bridges with a CFST skeleton. The span of these bridges has been increasing rapidly, which is rare in the history of bridge development. The large-scale construction of expressways and high-speed railways demands the development of long-span arch bridges, and advances in design and construction techniques have made it possible to construct such bridges. In the present study, the current status, development, and major innovative technologies of CFST arch bridges and concrete arch bridges with a CFST skeleton in China are elaborated. This paper covers the key con- struction technologies of CFST arch bridges, such as the design, manufacture, and installation of steel tube arch trusses, the preparation and pouring of in-tube concrete, and the construction of the world＇s longest CFST arch bridge-the First Hejiang Yangtze River Bridge. The main construction technologies of rein- forced concrete arch bridges are also presented, which include cable-stayed fastening-hanging cantilever assembly, adjusting the load by means of stay cables, surrounding the concrete for arch rib pouring, and so forth. In addition, the construction of two CFST skeleton concrete arch bridges-the Guangxi Yongning Yong River Bridge and the Yunnan-Guangxi Railway Nanpan River Bridge--is discussed. CFST arch bridges in China have already gained a world-leading position; with the continuous innovation of key technologies, China will become the new leader in promoting the development of arch bridges.
基金Research on in situ skin repair and regeneration based on micro-tissue engineering technology and 3D printing.(The National Key R&D Program of China,Grant Number 2019YFA0110503).The study on natural living micro-amniotic scaffolds to dynamic regulate immune inflammation and reconstruct wound repairing.(National Natural Science Foundation of China,Grant Number 81971836).The systemic study of miR-23b_24-1 cluster in the prevention and treatment of MODS caused by sepsis after burns.(National Natural Science Foundation of China,Grant Number 81930057).The experimental study on regulating the immune inflammatory microenvironment of burn wounds and promoting repair and regeneration based on micro-tissue engineering technology.(National Natural Science Foundation of China,Grant Number 81871559).
文摘Because China is becoming an aging society,the incidence of diabetes and diabetic foot have been increasing.Diabetic foot has become one of the main health-related killers due to its high disability and mortality rates.Negative pressure wound therapy(NPWT)is one of the most effective techniques for the treatment of diabetic foot wounds and great progress,both in terms of research and its clinical application,has been made in the last 20 years of its development.However,due to the complex pathogenesis and management of diabetic foot,irregular application of NPWT often leads to complications,such as infection,bleeding and necrosis,that seriously affect its treatment outcomes.In 2020,under the leadership of Burns,Trauma and Tissue Repair Committee of the Cross-Straits Medicine Exchange Association,the writing group for‘Consensus on the application of negative pressure wound therapy of diabetic foot wounds’was established with the participation of scholars from the specialized areas of burns,endocrinology,vascular surgery,orthopedics and wound repair.Drawing on evidence-based practice suggested by the latest clinical research,this consensus proposes the best clinical practice guidelines for the application and prognostic evaluation of NPWT for diabetic foot.The consensus aims to support the formation of standardized treatment schemes that clinicians can refer to when treating cases of diabetic foot.
基金Supported by the National Major Scientific Equipment Special Project(2012YQ16020304)
文摘Objective To explore the influence factors in hematoma formation after removing benign breast lesions with an ultrasound-guided vacuum-assisted system.Methods A total of 232 females with 312 benign breast masses received excisional biopsy with ultrasoundguided vacuum-assisted system.The pathology of patients,results of hematoma development and outcome,influence factors for hematoma occurrence(nodule size,nodule location,number of nodule,breast shape,menstrual period,efficacy time of bandage,and application of hemostatic agents during the procedure) were recorded.Results Pathologic examination revealed fibroadenomas in 138 lesions,fibroadenosis in 127 lesions,intraductal papillomas in 39 lesions,inflammatory change in 4 lesions,retention cyst of the breast in 3 lesions,and benign phyllodes tumor in 1 lesion.Thirty hematomas were observed in patients(9.6%).Finally,97.0%hematomas were absorbed completely within 6 months follow-up.The incidence rates of hematoma were increased by 24.7%,10.0%,63.2%,13.9%in the nodule diameter larger or equal to 25 mm group,removal of larger or equal to two nodules once time from one patient group,menstrual period group,and larger and loose breast group,respectively(all P<0.05).However,the incidences were decreased by 60.6%in the bandage performed for 12-24 hours or beyond 24 hours group(P<0.05).The multiple logistic regression models revealed that nodule size(x^2=15.227,P<0.001),number of nodule(x^2=7.767,P=0.005),menstrual period(x^2=24.530,P<0.001),and breast shape(x^2=9.559,P=0.002) were independent risk factors associated with hematoma occurrence,but efficacy time of bandage was a protective factor associated with hematoma occurrence.Conclusion The occurrence of hematoma after the minimally invasive operation was associated with nodule size,number of nodule,menstrual period,breast shape,and efficacy time of bandage.
基金the financial support of the National Science and Technology Major Project of the Ministry of Science and Technology of China(Grant No. 2012ZX04012011)the National Natural Science Foundation of China(Grant No.51275269)the Independent Research Program of Tsinghua University(Grant No.20121087918)
文摘The structures in vacuum-assist high-pressure die casting （HPDC） AM60B alloy were studied by using an optical microscope and a scanning electron microscope with an energy dispersive spectrometer. It was found that the HPDC under the vacuum could significantly change the morphology and distribution of the microstructure. For both conventional and vacuum-assist HPDC processes, the externally solidified crystals （ESCs） tended to aggregate in the center along the thickness direction of the castings. Besides, the aggregation was more pronounced, and the number of ESCs decreased, and the ESCs tended to become smaller and more globular, as the distance between the specimen location and runner increased. Compared with the conventional castings, the vacuum-assist HPDC can significantly reduce the size and amount of ESCs, and the ESCs tended to be more globular. For the distribution of ESCs along the thickness of the specimens, the aggregation tendency was more pronounced in vacuum-assist die castings than that in conventional castings. Besides, the distribution of ESCs at different locations was more converged in the vacuum-assist HPDC than that in the conventional HPDC.
文摘There is increasing concern about the safety of homologous blood transfusion during cardiac surgery,and a restrictive transfusion practice is associated with improved outcome.Transfusion-free pediatric cardiac surgery is unrealistic for the vast majority of procedures in neonates or small infants;however,considerable progress has been made by using techniques that decrease the need for homologous blood products or even allow bloodless surgery in older infants and children.These techniques involve a decrease in prime volume by downsizing the bypass circuit with the help of vacuumassisted venous drainage,microplegia,autologous blood predonation with or without infusion of recombinant(erythropoietin),cell salvaging,ultrafiltration and retrograde autologous priming.The three major techniques which are simple,safe,efficient,and cost-effective are:a prime volume as small as possible,cardioplegia with negligible hydric balance and circuit residual blood salvaged without any alteration.Furthermore,these three techniques can be used for all the patients,including emergencies and small babies.In every pediatric surgical unit,a strategy to decrease or avoid blood bank transfusion must be implemented.A strategy to minimize transfusion requirement requires a combined effort involving the entire surgical team with pre-,peri-,and postoperative planning and management.
基金Science and Technology Plan Project of Guizhou Province(No.[2019]1084 and[2018]5781)National Natural Science Foundation of China(No.51963003)+3 种基金The Youth Science and Technology Talent Growth Project of Guizhou Province Education Department(No.[2018]106)Outstanding Youth Program of Guizhou Province(No.20170439178)The Key project of Fundamental research in Guizhou province[2020]1Z044Scientific Research Project of Introduced Talents of Guizhou University(No.(2017)07)are acknowledged for the financial support.
文摘Some precision electronics such as signal transmitters need to not only emit effective signal but also be protected from the external electromagnetic(EM)waves.Thus,directional electromagnetic interference(EMI)shielding materials(i.e.,when the EM wave is incident from different sides of the sample,the EMI shielding effectiveness(SE)is rather different)are strongly required;unfortunately,no comprehensive literature report is available on this research field.Herein,Nicoated melamine foams(Ni@MF)were obtained by a facile electroless plating process,and multiwalled carbon nanotube(CNT)papers were prepared via a simple vacuum-assisted self-assembly approach.Then,step-wise asymmetric poly(butylene adipate-co-terephthalate)(PBAT)composites consisting of loose Ni@MF layer and compact CNT layer were successfully fabricated via a facile solution encapsulation approach.The step-wise asymmetric structures and electrical conductivity endow the Ni@MF/CNT/PBAT composites with unprecedented directional EMI shielding performances.When the EM wave is incident from Ni@MF layer or CNT layer,Ni@MF-5/CNT-75/PBAT exhibits the total EMI SE(SET)of 38.3 and 29.5 dB,respectively,which illustrates theΔSET of 8.8 dB.This work opens a new research window for directional EMI shielding composites with step-wise asymmetric structures,which has promising applications in portable electronics and next-generation communication technologies.
文摘To editor:Shoulder dystocia(SD)constitutes an obstetric emergency,bearing associations with maternal and neonatal morbidity due to its unique pathophysiology.In a comprehensive series involving 228,438 women,SD occurred in 2159 patients,accounting for 1.7%of the total.1 Various techniques have been described to facilitate successful delivery in SD patients;2 however,these maneuvers are not without associated complications.3 This correspondence highlights a case of a newborn experiencing a collapse following such a delivery.The guardian granted written and informed consent for the publication of the patient’s clinical information and associated images.
文摘Diamond/aluminium composites have attracted attention in the field of thermal management of electronic packaging for their excellent properties.In order to solve the interfacial problem between diamond and aluminium,a novel process combining pressure infiltration with vacuum-assisted technology was proposed to prepare diamond/aluminum composites.The effect of diamond particle size on the microstructure and properties of the diamond/Al-12Si composites was investigated.The results show that the diamond/Al-12Si composites exhibit high relative density and a uniform microstructure.Both thermal conductivity and coefficient of thermal expansion increase with increasing particle size,while the bending strength exhibits the opposite trend.When the average diamond particle size increases from 45μm to 425μm,the thermal conductivity of the composites increases from 455 W·m^(-1)·K^(-1)to 713 W·m^(-1)·K^(-1)and the coefficient of thermal expansion increases from 4.97×10^(-6)K^(-1)to 6.72×10^(-6)K^(-1),while the bending strength decreases from 353 MPa to 246 MPa.This research demonstrates that high-quality composites can be prepared by the vacuum-assisted pressure infiltration process and the thermal conductivity of the composites can be effectively improved by increasing the diamond particle size.
文摘BACKGROUND The diabetic foot is a common cause of disability and death,and comorbid foot infections usually lead to prolonged hospitalization,high healthcare costs,and a significant increase in amputation rates.And most diabetic foot trauma is complicated by lower extremity arteriopathy,which becomes an independent risk factor for major amputation in diabetic foot patients.AIM To establish the efficacy and safety of endovascular revascularization(ER)combined with vacuum-assisted closure(VAC)for the treatment of diabetic foot.METHODS Clinical data were collected from 40 patients with diabetic foot admitted to the Second Affiliated Hospital of Soochow University from April 2018 to April 2022.Diabetic foot lesions were graded according to Wagner’s classification,and blood flow to the lower extremity was evaluated using the ankle-brachial index test and computerized tomography angiography of the lower extremity arteries.Continuous subcutaneous insulin infusion pumps were used to achieve glycemic control.Lower limb revascularization was facilitated by percutaneous transluminal balloon angioplasty(BA)or stenting.Wounds were cleaned by nibbling debridement.Wound granulation tissue growth was induced by VAC,and wound repair was performed by skin grafting or skin flap transplantation.RESULTS Of the 35 cases treated with lower limb revascularization,34 were successful with a revascularization success rate of 97%.Of these,6 cases underwent stenting after BA of the superficial femoral artery,and 1 received popliteal artery stent implantation.In the 25 cases treated with infrapopliteal artery revascularization,39 arteries were reconstructed,7 of which were treated by drug-coated BA and the remaining 32 with plain old BA.VAC was performed in 32 wounds.Twenty-four cases of skin grafting and 2 cases of skin flap transplantation were performed.Two patients underwent major amputations,whereas 17 had minor amputations,accounting for a success limb salvage rate of 95%.CONCLUSION ER in combination with VAC is a safe and effective t
文摘Axillary lymph node status is one of the most important prognostic indicator of survival for breast cancer, especially in ductal carcinoma in situ （DCIS）. The purpose of this study was to investigate whether sentinel lymph node biopsy （SLNB） should be performed in patients with an initial diagnosis of DCIS. Methods： A retrospective study was performed of 124 patients with an initial diagnosis of DCIS between March 2000 and June 2014. The patients were treated with either SLNB or axillary node dissection during the surgery, and we compared the clinicopathologic characteristics, image features, and immunohistochemical results. Results： Eighty-two patients （66.1%） had pure DCIS and 25 （20.2%） had DCIS with microinvasion （DCISM）, 17 （13.7%） updated to invasive breast cancer （IBC）. 115 patients （92.7%） underwent SLNB, among them, 70 patients （56.5%） underwent axillary node dissection. 3 of 115 patients （2.6%） had a positive sentinel lymph node, only 1 （1.4%） of 70 patients had axillary lymph node metastasis, in 84 patients （66.7%） who were diagnosed DCIS by core needle biopsy （CNB） and vacuum-assisted biopsy （VAB）. 26 patients （31.0%） were upstaged into IBC or DCISM in the final histological diagnosis. The statistically significant factors predictive of underestimation were large tumor size, microcalcifications, comedo necrosis, positive Her-2 status, negative estrogen receptor status. Conclusion： The metastasis of sentinel lymph nodes in pure DCIS is very low, but the underestimation of invasive carcinoma in patients with an initial diagnosis of DCIS is an usual incident, especially in the cases when DCIS is diagnosed by CNB or VAB. Our findings suggest patients presenting with a preoperative diagnosis of DCIS associated with large tumor sizes, microcalcifications, comedo necrosis, positive Her-2 status, negative ER status are more likely to be DCISM and IBC in final diagnosis. SLNB should be performed in this part of patients.
文摘BACKGROUND Ductal carcinoma in situ(DCIS)arising within fibroadenoma is a type of tumor that is rarely encountered in clinic,with only about 100 cases of carcinoma arising within a fibroadenoma reported in the literature.Here,we present two cases of breast DCIS arising within a fibroadenoma and discuss their clinical and imaging findings as well as treatment.CASE SUMMARY The patients did not have cancer-related personal and family histories.Case 1(a 49-year-old woman)was diagnosed with a bilateral breast nodule in May 2018 and was followed(preoperative imaging data including ultrasound and mammography)for 3 years;she underwent an excisional biopsy to address an enlargement in nodule size.Case 2(a 37-year-old woman)was diagnosed with a left breast nodule in June 2021 and consequently received vacuum-assisted biopsy of the tumor which appeared as“irregularly shaped”and“unevenly textured”tissue on ultrasound.The pathological diagnosis was clear in both cases.Both patients underwent breast-conserving surgery and sentinel lymph node biopsy.The two cases received or planned to receive radiotherapy as well as endocrine therapy(tamoxifen).CONCLUSION Breast DCIS arising within a fibroadenoma is rare,but patients treated with radiotherapy and endocrine therapy can have good prognosis.
基金supported by the National Natural Science Foundation of China(61774046)。
文摘The demand for lightweight, flexible, and high-performance portable power sources urgently requires high-efficiency and stable flexible solar cells. In the case of perovskite solar cells(PSCs), most of the common electron transport layer(ETL) needs to be annealed for improving the optoelectronic properties,while conventional flexible substrates could barely stand the high temperature. Herein, a vacuumassisted annealing SnO_(2) ETL at low temperature(100℃) is utilized in flexible PSCs and achieved high efficiency of 20.14%. Meanwhile, the open-circuit voltage(V_(oc)) increases from 1.07 V to 1.14 V. The flexible PSCs also show robust bending stability with 86.8% of the initial efficiency is retained after 1000 bending cycles at a bending radius of 5 mm. X-ray photoelectron spectroscopy(XPS), atomic force microscopy(AFM), and contact angle measurements show that the density of oxygen vacancies, the surface roughness of the SnO_(2) layer, and film hydrophobicity are significantly increased, respectively. These improvements could be due to the oxygen-deficient environment in a vacuum chamber, and the rapid evaporation of solvents. The proposed vacuum-assisted low-temperature annealing method not only improves the efficiency of flexible PSCs but is also compatible and promising in the large-scale commercialization of flexible PSCs.
文摘Background: Deep sternal wound infection (DSWI), or mediastinitis, is a devastating complication of coronary artery bypass grafting (CABG). This prospective study aimed to assess our management of DSWI in view of the published literature. Methods: Over 2-years (ending in January 2016), 29 patients (20 males) developed DSWI amongst 520 patients who underwent standard CABG surgeries (5.6%). Pre-, intra- and postoperative variables were documented. Whenever possible, the infections were culture-verified. Besides antibiotics, patients received one or more of the following therapies: drainage, debridement, closed irrigation, sternal re-wiring, vacuum-assisted closure (VAC), and bone resection. Results: the male to female ratio was 2.2:1. Mean age was 58.1 ± 7.3 years. The mean body mass index (BMI) was 27.9 ± 3.4 kg/m<sup>2</sup>. There were 18, 16 and 11 patients with diabetes mellitus (DM), hypertension and chronic obstructive pulmonary disease (COPD) respectively. Cardiopulmonary bypass (CPB) was utilized in 26 (89.7%) patients with a mean time of 117.5 ± 23.3 minutes. Most surgeries (n = 21, 72.4%) lasted 5 - 6 hrs. According to Pairolero classification, there were 3 (10.3%) Type I, 22 (75.9%) Type II and 4 (13.8%) Type III infections. Four (13.8%) cases were culture-verified. Twenty-three (79.3%) DSWIs were surgically managed. Sternal re-wiring was performed in 14 (48.3%) cases while VAC was added to other therapies in 2 (6.9%) patients. DSWIs completely resolved in 18 (62.0%) patients within 3 - 24 weeks while two (6.9%) patients died within 30 days. Conclusion: We have identified six independent risk factors for DSWI (male gender, obesity, DM, hypertension, COPD and CPB), five of them are modifiable.
文摘Vacuum-assisted breast biopsy (VABB) plays a fundamental role in the preoperative assessment of breast lesions pro- viding large histology samples that are useful to define diagnoses and biological parameters to guide treatment planning. This technique has been used in our institute since 2000 and two new wireless handheld ultrasound-guided VABB de- vices have been introduced since May 2012. In this report we analyze our experience with these revolutionary devices which are able to provide the option of single-insertion contiguous tissue samples respectively with a 13/14-gauge aperture. Our initial experience on 75 lesions shows that these devices are safe, fast, procedurally advantageous for operators and well accepted by patients. Finally VABB procedures can markedly reduce the need for surgical biopsy.
