Effects of diamond particle size on microstructure and properties of diamond/Al-12Si composites prepared by vacuum-assisted pressure infiltration

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.

Clinical efficacy of endovascular revascularization combined with vacuum-assisted closure for the treatment of diabetic foot

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 treatment for diabetic foot that can significantly improve limb salvage rates.The use of VAC after ER simplifies and facilitates wound repair.

Percutaneous Removal of Benign Breast Lesions with an Ultrasound-guided Vacuum-assisted System:Influence Factors in the Hematoma Formation

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.

Highly efficient flexible perovskite solar cells with vacuum-assisted low-temperature annealed SnO2 electron transport layer

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.

Is sentinel lymph node biopsy necessary for the patients diagnosed with breast ductal carcinoma in situ using core needle biopsy or vacuum-assisted biopsy as the initial diagnostic method？

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.

New Wireless Handheld Ultrasound-Guided Vacuum-Assisted Breast Biopsy (VABB) Devices: An Important Innovation in Breast Diagnosis

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.

Diagnosis and excision of breast multi-focal lesions by ultrasound-guided vacuum-assisted biopsy:a comparative evaluation

Objective To compare and evaluate the efficacy of diagnosis and excision for appropriately selected breast multi-focal lesions and solitary lesion by ultrasound-guided vacuum-assisted biopsy(UGVAB).Methods Among 392 appropriately selected patients,187 patients with multi-focal lesions and 205 patients with solitary lesion were treated by the 8-gauge UGVAB from May 2007 to June 2009.All lesions were removed as completely as possible.The patients with benign pathology underwent physical and ultrasound examinations at one week and 6 months after procedure.Results During the procedure,only three patients had vasovagal syncope and twenty others complained of other intraoperative discomfort.An accurate pathological diagnosis was obtained in all lesions.There was no apparent false-negative result among the 696 lesions with benign pathology at a follow-up of 6 months after procedure.The rates of malignant or premalignant pathology,postoperative complications and residual lesions in patients with multi-focal lesions were higher than those in patients with solitary lesion.If each lesion was considered as a subject of study,there was no significant difference between the two groups.Conclusion UGVAB is an effective method for diagnosis and excision of appropriately selected breast multi-focal lesions and can be used routinely.

Efficacy and prognosis of vacuum-assisted excision for benign intraductal papilloma of breast:A meta-analysis

Objective:To evaluate the safety and effectiveness of vacuum-assisted excision for benign intraductal papilloma of breast.Methods:The databases including PubMed,Embase,Cochrane Library,WangFang,CNIK,VIP and Web of Science were searched by computer,according the inclusion and exclusion criteria after screening of literature.The Cochrane handbook and Newcastle-Ottawa scale was used to evaluate the studies.Then the Review Manager 5.3 software was to used analyze the data.Results:A total of 1016 patients was included in 9 articles.The amount of blood loss in vacuum-assisted surgery was less than that in open surgery[MD=-6.38,95%CI(-9.90,-2.86),P<0.05].The drainage[MD=-2.56,95%CI(-4.97,-0.15,P<0.05]and drainage time[MD=-0.25,95%CI(-0.40,-0.09),P<0.05]in vacuum-assisted surgery was less than that in open surgery.There were also few postoperative complications than that in open surgery[RR=0.43,95%CI(0.29,0.64),P<0.05].Compared with open surgery,the postoperative recurrence rate was lower in vacuum-assisted surgery[RR=0.26,95%CI(0.14,0.49),P<0.05].Last,there was no statistically significant difference in the operative time between vacuum-assisted surgery and open surgery,[SD=-12.82,95%CI(-25.70,0.06),P=0.05].Conclusion:Compared with open surgery,vacuum-assisted excision has the advantages of less blood loss and lower postoperative complications,but the operative time is not statistically significant compared with open surgery.In addition,compared with open surgery in this study,vacuum-assisted excision has the advantages of lower recurrence rate,but it still needs long-term dynamic observation.

Comparison of the underestimation rate in cases with ductal carcinoma in situ at ultrasound-guided core biopsy: 14-gauge automated core-needle biopsy vs 11-gauge vacuum-assisted biopsy

Objective： The objective of this study was to compare the underestimation rate of invasive carcinoma cases with ductal carcinoma in situ （DCIS） at percutaneous ultrasound-guided core biopsies of breast lesions between 14-gauge automated core needle biopsy （ACNB） and 11-gauge vacuum-assisted biopsy （VAB）, and analyze the diagnostic advantages and insufficiencies in DCIS between this two methods, and to determine the relationship between the lesion type （masses or microcalcifications on radiological findings ） and DCIS underestimation rate. Methods： We collected 152 breast lesions which were diagnosed as DCIS by retrospectively reviewing data about ultrasound-guided biopsies of breast lesions （from February 2003 to July 2010）. There were 98 lesions in 95 patients by 14-gauge ACNB, and 54 lesions in 52 patients by 11-gauge VAB （The system used in this study called Mammatome, MMT）. The clinical and radiological findings were reviewed; meanwhile all the selected patients had histological results of the biopsies and follow-up surgeries which also achieved the reliable pathological results to compare with the biopsy results. The differences between two correlated histological results defined as underestimation, and the histological DCIS underestimation rates were compared between the two groups. According to the radiological characteristics, each group was classified into two subgroups （masses or micrecalcifications group）, and the differences between subgroups were also analyzed. Results： The DCIS underestimation rate was 45.9% （45/98） for 14-gauge ACNB and 16.6% （9/54） for MMT. According to the lesion type on ultrasonography, DCIS underestimation was 31.0% （26/84） in masses （43.1% using ACNB and 12.1% using MMT; P = 0.003） and 42.6% （29/68） in microcalcifications （48.9% using ACNB and 23,8% using MMT; P = 0,036）, Conclusion： The underestimation rate of invasive carcinoma in cases with DCIS at ultrasound-guided core biopsies is significantly higher for ACNB than for MMT. Furthermore, this difference does not alter among the two lesion types presented on ultrasonography. So ultrasound-guided VAB （MMT system） could be an effective and useful method for the diagnosis of DCIS lesions no matter what the lesion type is.

Efficacy and Safety of Ultrasound Guided Vacuum-Assisted Excision of Fibroadenomas: A Systematic Review

Background: Ultrasound-guided, vacuum-assisted excision [UGVAE] of fibroadenomas is an emerging minimally invasive procedure. UGVAE is being increasingly employed by breast radiologists and surgeons. It has been approved for this use since 2006 by the National Institute for Health and Clinical Excellence in the UK. The aim of this systematic review is to evaluate the efficacy and safety of this procedure based on the up to date available evidence. Methods: A comprehensive literature search of the Cochrane library, Medline, Embase, PubMed, Google scholar, Trip-database, Internet, and the reference lists of relevant articles was performed. We searched for literature with sizeable cases of therapeutic vacuum-assisted excision of fibroadenomas. All prospective studies with more than 20 study participants were screened. The study quality was assessed using the Grading of Recommendations Assessment, Development, and Evaluation [GRADE] approach. All were in English. Results: Of the four case series that fulfilled the inclusion criteria there were 516 patients in which 520 procedures were performed. Overall complete excision rate was 89.4%. In two of the studies, this was 100% when the lesions were less than 1.5 cm but reduced to 61% when between 1.5 and 2 cm. Most common significant complication was bleeding with 2 cases of pneumothorax. None of the studies can be regarded as high quality going by GRADE approach. Conclusion: Within the limit of the current published case series, UGVAE appears to be an effective and safe procedure for excision of small fibroadenomas of less than 15 mm in size. A well designed case control study or randomized controlled trials with a sufficient sample size is needed to further assess its safety, effectiveness and more importantly, patients’ satisfaction especially in larger sized fibroadenomas.

Effectiveness of negative pressure wound therapy in complex surgical treatment of necrotizing fasciitis of the upper limb

BACKGROUND Necrotizing fasciitis(NF)of the upper extremities is a severe surgical pathology,and the incidence of this disease has been steadily increasing in recent decades.Surgical treatment is accompanied by the formation of extensive wounds,which can be treated with significant difficulties.In recent years,negative pressure wound therapy(NPWT)has proven to be highly effective.It is also promising for the treatment of NF.AIM To explore the effectiveness of NPWT in the treatment of NF of the upper extremities.METHODS The results of the treatment of 36 patients with NF of the upper extremities in two groups(NPWT group and control group;2022−2023)were retrospectively analyzed.In the NPWT group,the NPWT method(120 mmHg;constant mode)was used after surgical treatment.The number of vacuum-assisted dressings in patients ranged from 1 to 3,depending on the dynamics of the wound process.The duration of fixation of one bandage was up to 2−3 d.In the control group,conventional methods of local wound treatment were used.The following indicators were analyzed:The treatment delay,the prevalence of inflammation,the microbial landscape,the number of debridements,the duration of wound preparation for surgical closure,and the nature of skin plastic surgery.RESULTS Most patients experienced a significant treatment delay[4 d,interquartile range(IQR):2–7 d],which led to the spread of the pathological process to the forearm and shoulder.The most common pathogens were Staphylococcus aureus(14;38.9%)and Streptococcus pyogenes(22;61.1%).The average number of debridements per patient was 5(IQR:3–7),with no difference between groups.The average time to prepare wounds for surgical closure was 11±4 d in the NPWT group and 29±10 d(P=0.00001)in the control group.In the NPWT group,the wounds were more often closed with local tissues(15;83.3%),and in the control group,split-thickness skin grafts were more often used(4;50%).CONCLUSION The predominant isolation of Staphylococcus aureus and/or Streptococcus pyogenes from the lesions allowed us to classify these patients as NF type II.Multiple debridement procedures have become a feature of this disease treatment.The use of NPWT has significantly reduced the time required to prepare wounds for surgical closure.Early closure of wounds allows for more frequent use of local tissue repair,which ensures better results.NPWT is a highly effective way to prepare wounds for early surgical closure in patients with upper extremity NF.

How to preserve the native or reconstructed esophagus after perforations or postoperative leaks: A multidisciplinary 15-year experience

BACKGROUND Esophageal perforation or postoperative leak after esophageal surgery remain a life-threatening condition.The optimal management strategy is still unclear.AIM To determine clinical outcomes and complications of our 15-year experience in the multidisciplinary management of esophageal perforations and anastomotic leaks.METHODS A retrospective single-center observational study was performed on 60 patients admitted at our department for esophageal perforations or treated for an anastomotic leak developed after esophageal surgery from January 2008 to December 2023.Clinical outcomes were analyzed,and complications were evaluated to investigate the efficacy and safety of our multidisciplinary management based on the preservation of the native or reconstructed esophagus,when feasible.RESULTS Among the whole series of 60 patients,an urgent surgery was required in 8 cases due to a septic state.Fifty-six patients were managed by endoscopic or hybrid treatments,obtaining the resolution of the esophageal leak/perforation without removal of the native or reconstructed esophagus.The mean time to resolution was 54.95±52.64 days,with a median of 35.5 days.No severe complications were recorded.Ten patients out of 56(17.9%)developed pneumonia that was treated by specific antibiotic therapy,and in 6 cases(10.7%)an atrial fibrillation was recorded.Seven patients(12.5%)developed a stricture within 12 months,requiring one or two endoscopic pneumatic dilations to solve the problem.Mortality was 1.7%.CONCLUSION A proper multidisciplinary approach with the choice of the most appropriate treatment can be the key for success in managing esophageal leaks or perforations and preserving the esophagus.

A new vacuum-assisted low-pressure investment casting process for K446 alloy

Non-metallic inclusions and zyglo indications frequently occur in the superalloy castings produced through the traditional vacuum gravity investment casting process,particularly in components with thin-walled and complex structural features.The vacuum-assisted low-pressure casting(VLC),a type of counter-gravity casting(CGC)method,has been developed to minimize non-metallic inclusions and zyglo indications in superalloy castings.Rectifying frames for gas turbines made from K446 alloy were produced semi-continuously using the VLC process and subsequently evaluated through tensile testing,chemical composition analysis,X-ray diffraction,and zyglo penetrant inspection.The results indicate a roughly 10%improvement in tensile strength at 800℃ compared to gravity casting.Moreover,no significant changes are observed in the chemical composition of the alloys from the beginning to the end of a casting campaign,indicating that the developed VLC process is viable for the engineering-scale production of superalloy castings.Compared to traditional vacuum gravity casting(GC)method,the application of VLC can reduce the numbers of non-metallic inclusions and Zyglo indications in the castings by over 80%.At the same time,it significantly shortens the production time by 3 to 5 days.

Directional Electromagnetic Interference Shielding Based on Step-Wise Asymmetric Conductive Networks

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.

Perfusionist strategies for blood conservation in 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.

Preoperational diagnosis and management of breast ductal carcinoma in situ arising within fibroadenoma:Two case reports

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.

Concrete-Filled Steel Tube Arch Bridges in China

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.

Negative Pressure Wound Therapy—An Effective, Minimally Invasive Therapeutic Modality in Burn Wound Management

Despite the advancement in burn therapy in the last decades the treatment of burn wounds still remains a challenging task. Infection is still a common complication;while sepsis remains the leading cause of death in severe burns. The research guided integration of new and effective techniques in burn wound management is mandatory. Negative pressure wound therapy (NPWT) is an effective and widely used technique in the management of problematic wounds. Previously existing indications include soft tissue traumas and chronic wounds such as diabetic, arterial, venous and pressure ulcers. The characteristics and challenges of these wounds have a lot in common with burns. Since the early 2000’s there are experiences with the use of NPWT for the healing of second degree burn wounds. Our clinical experience shows that it is a minimally invasive and effective way of improving burn wound management. In this article we give a review of the literature showing the mechanisms, unmapped future opportunities, financial issues, and possible adverse effects of NPWT in burn therapy.

Deep Sternal Wound Infections after Coronary Artery Bypass Grafting: Analysis of 29 Cases from Iraq

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/m2. 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.

Characterization of the Grain Structures in Vacuum-Assist HighPressure Die Casting AM60B Alloy

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.