This study focuses on finding a solution to the sharp decline in mechanical properties of Al-Si-Cu-Mg alloys due to rapid coarsening of traditional intermediate phases at high temperature.A new type of modified al oy,...This study focuses on finding a solution to the sharp decline in mechanical properties of Al-Si-Cu-Mg alloys due to rapid coarsening of traditional intermediate phases at high temperature.A new type of modified al oy,to be used in automobile engines at high temperatures,was prepared by adding Zr and Mo into Al-Si-Cu-Mg alloy.The synergistic effects of Zr and Mo on the microstructure evolution and high-temperature mechanical properties were studied.Results show that the addition of Zr and Mo generates a series of intermetallic phases dispersed in the alloy.They can improve the strength of the alloy by hindering dislocation movement and crack propagation.In addition,some nano-strengthened phases show coherent interfaces with the matrix and improve grain refinement.The addition of Mo greatly improves the heat resistance of the alloy.The extremely low diffusivity of Mo enables it to improve the thermal stability of the intermetallic phases,inhibit precipitation during aging,reduce the size of the precipitates,and improve the heat resistance of the alloy.展开更多
The application of ultrasonic vibration during the casting process has been proven to refine the microstructure and enhance the properties of the casting.By using the direct inserting method,wherein the ultrasonic hor...The application of ultrasonic vibration during the casting process has been proven to refine the microstructure and enhance the properties of the casting.By using the direct inserting method,wherein the ultrasonic horn is inserted directly into the melt,ultrasonic treatment can be utilized in the semi-continuous casting process to produce aluminum ingots with simple shapes.However,due to the attenuation of ultrasound,it is challenging to apply the direct inserting method in the die casting process to produce complex castings.Thus,in this study,the impact of ultrasonic vibration on the microstructure of a gravity die-cast AlSi9Cu3end cap was investigated by applying ultrasonic vibration on the core(indirect method).It is found that the effect of ultrasonic vibration relies greatly on the resonance mode of the core.Selection of ultrasonic vibration schemes mainly depends on the core structure,and only a strong vibration can significantly refine the microstructure of the casting.For castings with complex structures,an elaborated ultrasonic vibration design is necessary to refine the microstructure of the specified casting.In addition,strong vibration applied on the feeding channel can promote the feeding ability of casting by breaking the dendrites during solidification,and consequently reduce the shrinkage porosity.展开更多
AIM: To investigate the feasibility of compression anastomosis clip (CAC) for gastrointestinal anastomosis proximal to the ileocecal junction. METHODS: Sixty-six patients undergoing gastrointe-stinal anastomosis proxi...AIM: To investigate the feasibility of compression anastomosis clip (CAC) for gastrointestinal anastomosis proximal to the ileocecal junction. METHODS: Sixty-six patients undergoing gastrointe-stinal anastomosis proximal to the ileocecal junction were randomized into two groups according to the anastomotic method, CAC or stapler. RESULTS: The postoperative recovery of patients in CAC and stapled anastomosis groups was similar. No postoperative complication related to the anastomotic method was found in either group. Both upper gastrointestinal contrast radiography at the early postoperative course and endoscopic examination after a 6-mo follow-up showed a better healing at the compression anastomosis. CONCLUSION: CAC can be used not only in colonic surgery but also in gastrointestinal anastomosis. Our result strongly suggests that CAC anastomosis is safe in various complication circumstances. However, it should be further conf irmed with a larger patient sample.展开更多
A pinned photodiode complementary metal–oxide–semiconductor transistor(CMOS) active pixel sensor is exposed to ^60Co to evaluate the performance for space applications. The sample is irradiated with a dose rate of...A pinned photodiode complementary metal–oxide–semiconductor transistor(CMOS) active pixel sensor is exposed to ^60Co to evaluate the performance for space applications. The sample is irradiated with a dose rate of 50 rad(SiO2)/s and a total dose of 100 krad(SiO2), and the photodiode is kept unbiased. The degradation of dark current, full well capacity,and quantum efficiency induced by the total ionizing dose damage effect are investigated. It is found that the dark current increases mainly from the shallow trench isolation(STI) surrounding the pinned photodiode. Further results suggests that the decreasing of full well capacity due to the increase in the density, is induced by the total ionizing dose(TID) effect, of the trap interface, which also leads to the degradation of quantum efficiency at shorter wavelengths.展开更多
Objective To investigate whether asbestosis is a risk factor for mortality of lung cancer. Methods A fixed cohort study was established in an asbestos plant in Chongqing, China, and followed up for 30 years from the b...Objective To investigate whether asbestosis is a risk factor for mortality of lung cancer. Methods A fixed cohort study was established in an asbestos plant in Chongqing, China, and followed up for 30 years from the beginning of 1972. Basic personal information on life state, cause of death, and diagnosis of asbestosis was collected. Multiple logistic regressions were applied to analyze risk factors. Results During the 30-year follow-up, 584 male workers constituting a total of 14 664 person-years were monitored and data were analyzed. Among them, 203 (34.8%) died and the mortality rate was 13.8 per 1000 person-years, cancer accounting for 37.4%. Excess risks were observed for lung cancer (OR=3.72) and nonmalignant respiratory diseases (OR=2.73) among workers with asbestosis. High-exposure level was another risk factor for lung cancer (OR-3.20). Workers with category II of asbestosis demonstrated a higher OR of both lung cancer and nonmalignant respiratory diseases than those with category I of asbestosis. Conclusion High asbestos exposure level and asbestosis were the risk factors for death of lung cancer and nonmalignant respiratory diseases. Asbestosis is an independent risk factor for lung cancer among Chinese workers exposed to chrysotile, the risk increases with the increasing profusion of opacities of lung.展开更多
Polycystic liver disease(PLD)is a rare hereditary disease that independently exists in isolated PLD,or as an accompanying symptom of autosomal dominant polycystic kidney disease and autosomal recessive polycystic kidn...Polycystic liver disease(PLD)is a rare hereditary disease that independently exists in isolated PLD,or as an accompanying symptom of autosomal dominant polycystic kidney disease and autosomal recessive polycystic kidney disease with complicated mechanisms.PLD currently lacks a unified diagnostic standard.The diagnosis of PLD is usually made when the number of hepatic cysts is more than 20.Gigot classification and Schnelldorfer classification are now commonly used to define severity in PLD.Most PLD patients have no clinical symptoms,and minority with severe complications need treatments.Somatostatin analogues,mammalian target of rapamycin inhibitor,ursodeoxycholic acid and vasopressin-2 receptor antagonist are the potentially effective medical therapies,while cyst aspiration and sclerosis,transcatheter arterial embolization,fenestration,hepatic resection and liver transplantation are the options of invasion therapies.However,the effectiveness of these therapies except liver transplantation are still uncertain.Furthermore,there is no unified strategy to treat PLD between medical centers at present.In order to better understand recent study progresses on PLD for clinical practice and obtain potential directions for future researches,this review mainly focuses on the recent progress in PLD classification,clinical manifestation,diagnosis and treatment.For information,we also provided medical treatment processes of PLD in our medical center.展开更多
The application of ultrasonic vibration to the casting process can be realized through mould(die)vibration.However,the resonant vibration of the mould is always accompanied by a non-uniform vibration distribution at d...The application of ultrasonic vibration to the casting process can be realized through mould(die)vibration.However,the resonant vibration of the mould is always accompanied by a non-uniform vibration distribution at different parts,which may induce a complex liquid flow and affect the casting fluidity during the mould filling process.The influence of non-uniform ultrasonic vibration on the fluidity of liquid AlSi9Cu3 alloy was studied by mould vibration with different vibration gradients.It is found that ultrasonic mould vibration can generate two opposite effects on the casting fluidity:the first,ultrasonic cavitation in melt induced by mould vibration promotes the casting fluidity;the second,the non-uniform mould vibration can induce a melt flow toward the weak vibration areas and turbulence there,consequently decreasing the casting fluidity.When the melt flow and turbulence are violent enough to offset the promoting effect of cavitation on fluidity,the ultrasonic vibration will finally induce a resultant decrease of casting fluidity.The decreasing effect is proportional to the vibration gradient.展开更多
Objective:To explore the role of bone morphogenetic protein 4(BMP-4) in hepatic progenitor cells(HPCs).Methods:The effect of BMP-4 on rat hepatic oval cells was examined by using the WB-F344 rat hepatocytic epithelial...Objective:To explore the role of bone morphogenetic protein 4(BMP-4) in hepatic progenitor cells(HPCs).Methods:The effect of BMP-4 on rat hepatic oval cells was examined by using the WB-F344 rat hepatocytic epithelial stem-cell-like cell line.This hepatocytic cell line could exert various hepatocytc functions including the secretion of albumin and urea.Immunohistochemistry was used to examine the effects of BMP-4 and its antagonist,Noggin,on the proliferation and differentiation of these cells,cellular uptake and excretion of indocyanine green,the periodic acid-schiff(PAS) assay for glycogen storage and the expression of hepatic markers.Results:Our results showed for the first time that BMP-4 may acted as a potential inducer of hepatic differentiation in rat hepatic oval cells.Conclusions:This cell source offers a much-needed attractive and expandable source for future investigations of drug screening,stem cell technologies and cellular transplantation,in a society with increasing levels of liver disease and damage.展开更多
Cholangiocarcinoma refers to malignant tumors that develop in epithelial lining of biliary system, and it is divided into two categories according to tumor location, intrahepatic cholangiocarcinoma (ICC) and extrahe...Cholangiocarcinoma refers to malignant tumors that develop in epithelial lining of biliary system, and it is divided into two categories according to tumor location, intrahepatic cholangiocarcinoma (ICC) and extrahepatic cholangiocarcinoma (ECC). ICC occurs from the epithelial cells of the intrahepatic bile duct, its branches and interlobular biliary tree; and ECC is divided into hilar cholangiocarcinoma and distal cholangiocarcinoma by the circumscription at the confluence of cystic duct and the common hepatic duct.展开更多
BACKGROUND Papillary cystadenoma is a rare benign epithelial tumor of the salivary gland,which is characterized by papillary structures and oncocytic cells with rich eosinophilic cytoplasm. We found only one case of p...BACKGROUND Papillary cystadenoma is a rare benign epithelial tumor of the salivary gland,which is characterized by papillary structures and oncocytic cells with rich eosinophilic cytoplasm. We found only one case of papillary cystadenoma in nearly 700 cases of salivary gland tumors. Our case was initially mistaken for a tumor of the right temporomandibular joint(TMJ) capsule rather than of parotid gland origin. Preoperative magnetic resonance imaging(MRI) and computed tomography(CT) should be carefully studied, which allows for appropriate preoperative counseling and operative planning.CASE SUMMARY Here, we report an unusual case of a 54-year-old woman with a parotid gland papillary cystadenoma(PGPC) that was misdiagnosed as a tumor of the right TMJ capsule. She was initially admitted to our hospital due to a mass anterior to her right ear inadvertently found 5 d ago. Preoperative CT and MRI revealed a well circumscribed tumor that was attached to the right TMJ capsule. The patient underwent a resection through an incision for TMJ, but evaluation of an intraoperative frozen section revealed a benign tumor of the parotid gland. Then we removed part of the parotid gland above the temporal facial trunk. The facial nerve was preserved. Postoperative histopathological findings revealed that the tumor was PGPC. No additional treatment was performed. There was no recurrence during a 20-mo follow-up period.CONCLUSION The integrity of the interstitial space around the condyle in MRI or CT should be carefully evaluated for parotid gland or TMJ tumors.展开更多
Chiral metamaterial absorbers(CMMAs),a particular class of chiral metamaterials that refuse the transmission of incident radiation and exhibit different optical responses upon interactions with left and right circular...Chiral metamaterial absorbers(CMMAs),a particular class of chiral metamaterials that refuse the transmission of incident radiation and exhibit different optical responses upon interactions with left and right circularly polarized(RCP)light,have gained research traction in recent years.CMMAs demonstrate numerous exotic and specialized applications owing to their achievable compatibility with various physical,chemical,and biomolecular systems.Aside from their well-evolved fabrication modalities for a broad range of frequencies,CMMAs exhibit strong chiroptical effects,making them central to various detection,imaging,and energy harvesting applications.Consequently,within the past decade,studies encompassing the design,optimization,and fabrication,as well as demonstrating the diverse applications of CMMAs have emerged.In this review,the theory,design,and fabrication of CMMAs are discussed,highlighting their top-down fabrication techniques as well as recent algorithmic and machine-learning(ML)-based approaches to the design and optimization.Some of their broad-spectrum applications are also discussed,spanning their roles in enantioselective photodetection,chiral imaging,generation of hot electrons,selective temperature sensing,and active chiral plasmonics.展开更多
Malignant lymphoma originates from the lymphohematopoietic system.It can occur in any lymphoid tissue.Malignant lymphoma of the salivary gland is rare,but its incidence has increased in recent years.Its clinical-prese...Malignant lymphoma originates from the lymphohematopoietic system.It can occur in any lymphoid tissue.Malignant lymphoma of the salivary gland is rare,but its incidence has increased in recent years.Its clinical-presentations are nonspecific,and it is often manifested as a painless mass in a salivary gland,which can be accompanied by multiple swollen cervical lymph nodes.Confirmation of the diagnosis before an invasive procedure is difficult.Clinically,malignant lymphoma of the salivary gland tends to be misdiagnosed,leading to an inappropriate treatment plan and the ultimate delay in the optimal treatment of the disease.This article reviews the pathogenesis,clinical features,imaging findings,diagnosis,treatment and prognosis of malignant lymphoma of the salivary gland.展开更多
BACKGROUND Multiple intraoral dermoid cysts of large magnitude generally appear in the second or third decade of life.They are rare in infants and are usually solitary.In this case,a large mass was identified in utero...BACKGROUND Multiple intraoral dermoid cysts of large magnitude generally appear in the second or third decade of life.They are rare in infants and are usually solitary.In this case,a large mass was identified in utero during prenatal exams.CASE SUMMARY We introduce a rare case on multiple dermoid cysts in the floor of the mouth of an infant who underwent two surgeries for this.Preoperative magnetic resonance imaging confirmed a large well-circumscribed cystic lesion that originated at the former midline region in the floor of the mouth in which a suspicious lesion of minute size was likely compressed by the bulkier mass and overlooked.Therefore,the infant underwent two surgeries by an intraoral approach within 9 mo.At 5 mo after the second operation,a routine follow-up ultrasound showed evidence of an additional cyst.No further surgery was planned because the tumor had no immediate effect.CONCLUSION This report demonstrates the importance of carefully analyzing preoperative imaging to avoid multiple operations for a seemingly isolated oral cyst.展开更多
BACKGROUND We report a case of essential thrombocythemia(ET)in a 44-year-old male who exhibited non-ST-segment-elevation myocardial infarction(NSTEMI)as the first manifestation without known cardiovascular risk factor...BACKGROUND We report a case of essential thrombocythemia(ET)in a 44-year-old male who exhibited non-ST-segment-elevation myocardial infarction(NSTEMI)as the first manifestation without known cardiovascular risk factors(CVRFs).For the first time,we reported a left main trifurcation lesion in NSTEMI caused by ET,including continuous stenosis lesions from the left main to the ostial left anterior descending(LAD)artery and an obvious thrombotic lesion in the ostial and proximal left circumflex(LCX)artery.There was 60%diffuse stenosis in the left main(LM)that extended to the ostial LAD,thrombosis of the ostial LAD and proximal LCX,and 90%stenosis in the proximal LCX.During the operation,thrombus aspiration was performed,but no obvious thrombus was aspirated.Performing the kissing balloon technique(KBT)in the LCX and LM unexpectedly increased the narrowness of the LAD.Then,the single-stent crossover technique,final kissing balloon technique and proximal optimization technique(POT)were performed.On the second day after percutaneous coronary intervention(PCI),the number of platelets(PLTs)still increased significantly to as high as 696×10^(9)/L.The bone marrow biopsy done later,together with JAK2(exon 14)V617F mutation,confirms the diagnosis of ET.Hydroxyurea was administered to inhibit bone marrow proliferation to control the number of PLTs.CASE SUMMARY A 44-year-old male patient went to a local hospital for treatment for intermittent chest pain occurring over 8 h.The examination at the local hospital revealed elevated cTnI and significantly elevated platelet.Then,he was diagnosed with acute myocardial infarction and transferred to our hospital for emergency interventional treatment by ambulance.During the operation,thrombus aspiration,the single-stent crossover technique,final kissing balloon technique and POT were performed.Dual antiplatelet therapy comprising aspirin and ticagrelor was used after PCI.Evidence of mutated JAK2 V617F and bone marrow biopsy shown the onset of ET.Together with JAK2(exon 14)V617F mutation,ET was diagnosed according to the World Health Organization(WHO)diagnostic criteria,and the patient was placed on hydroxyurea.During the one-year postoperative period,repeated examinations showed a slight increase in PLTs,but the patient no longer had chest tightness,chest pain or bleeding or developed new thromboembolisms.CONCLUSION Routine physical examinations and screenings are conducive to the early detection of ET,and the risk for thrombosis should be assessed.Then,active antiplatelet therapy and myelosuppression therapy should be used for high-risk ET patients.展开更多
Background:Enhanced recovery after surgery (ERAS) protocols or fast-track (FT) programs enable a shorter hospital stay and lower complication rate.Minimally invasive surgery (MIS) is associated with a lesser tr...Background:Enhanced recovery after surgery (ERAS) protocols or fast-track (FT) programs enable a shorter hospital stay and lower complication rate.Minimally invasive surgery (MIS) is associated with a lesser trauma and a quicker recovery in many elective abdominal surgeries.However,little is known of the safety and effectiveness made by ERAS protocols combined with MIS for gastric cancer.The purpose of this study was to evaluate the safety and effectiveness made by FT programs and MIS in combination or alone.Methods:We summarized an 11-year experience on gastric cancer patients undergoing elective laparotomy or minimally invasive gastric resection in standard cares (SC) or FT programs during January 2004 to December 2014.A total of 984 patients were enrolled and assigned into four groups:open gastrectomies (OG) with SC (OG + SC group,n =167);OG with FT programs (OG + FT group,n =277);laparoscopic gastrectomies (LG) with FT programs (LG + FT group,n =248);and robot-assisted gastrectomies (RG) with FT programs (RG + FT group,n =292).Patients' data were collected to evaluate the clinical outcome.The primary end point was the length of postoperative hospital stay.Results:The OG + SC group showed the longest postoperative hospital stay (mean:12.3 days,median:11 days,interquartile range [IQR]:6-16 days),while OG + FT,LG + FT,and RG + FT groups recovered faster (mean:7.4,6.4,and 6.6 days,median:6,6,and 6 days,IQR:3-9,4-8,and 3-9 days,respectively,all P 〈 0.001).The postoperative rehabilitation parameters such as flatus time after surgery (4.7 ± 0.9,3.1 ± 0.8,3.0± 0.9,and 3.1 ± 0.9 days) followed the same manner.After 30 postoperative days' follow-up,the total incidence of complications was 9.6% in OG + SC group,10.1% in OG + FT group,8.1% in LG + FT group,and 10.3% in RG + FT group.The complications showed no significant differences between the four groups (all P 〉 0.05).Conclusions:ERAS protocols alone could significantly bring fast recovery after surgery regardless of the surgical technique.MIS further reduces postoperative hospital stay.It is safe and effective to apply ERAS protocols combined with MIS for gastric cancer.展开更多
In this paper, we develop a new path search algorithm which considers all the degrees of freedom and apply it on our calculated five-dimensional potential energy surface(PES) of^(236) U. Asymmetric and symmetric fissi...In this paper, we develop a new path search algorithm which considers all the degrees of freedom and apply it on our calculated five-dimensional potential energy surface(PES) of^(236) U. Asymmetric and symmetric fission paths and barriers are obtained.展开更多
To investigate the effect of yttrium(Y) on microstructure refinement and mechanical properties of aluminum alloy A356.2,the different trace contents of Y(0 wt%,0.025 wt%,0.050 wt%,0.075 wt%,or 0.100 wt%)were introduce...To investigate the effect of yttrium(Y) on microstructure refinement and mechanical properties of aluminum alloy A356.2,the different trace contents of Y(0 wt%,0.025 wt%,0.050 wt%,0.075 wt%,or 0.100 wt%)were introduced into the liquid alloy.The alloys were fabricated in a preheated permanent mold,and subsequently treated by a T6 heat treatment.The results of tensile testing indicate that the yield strength(YS),the ultimate tensile strength(UTS) and the elongation(El) of the A356.2 alloy are improved by the Y additions.The YS dependence on grain size for the test alloys follows the Hall-Petch equation,which gives YS=-354.1+2875.2 d^(-1/2) with a correlation of R^(2)=0.83.As 0.050 wt%Y is added,the optimum values of the YS,UTS and El are achieved after T6 heat treatment.The secondary phases were identified by X-ray diffraction(XRD) which mainly consisted as Si,Mg2 Si and Al3 Y.The scanning electron microscope(SEM) and energy-dispersive spectrometer(EDS) analyses reveal the presence of the nano-sized Al3 Y particles on the surface of the Si phase.The A356.2 alloy with the Y addition is strengthened by the dendritic refinement,and the presence of the micron-and nano-sized Al3 Y precipitates.展开更多
Five-dimensional(5D)fission potential energy surfaces(PES)for uranium nuclei are investigated based on the macroscopic–microscopic Lublin–Strasbourg drop model in the threequadratic-surface parametrization,and the h...Five-dimensional(5D)fission potential energy surfaces(PES)for uranium nuclei are investigated based on the macroscopic–microscopic Lublin–Strasbourg drop model in the threequadratic-surface parametrization,and the heights of static fission barriers are obtained.Asymmetric and symmetric fission paths are presented on the 5D PES of 236U for different nuclear shapes.The calculated barrier heights,EAand EB,are quite consistent with the experimental data for all even–even nuclei of uranium isotopes,from 230U to 244U.展开更多
Background:Conservative therapy for Crohn’s disease(CD)-related acute bowel obstruction is essential to avoid emergent surgery.The present study aimed to evaluate the efficacy of using a long intestinal decompression...Background:Conservative therapy for Crohn’s disease(CD)-related acute bowel obstruction is essential to avoid emergent surgery.The present study aimed to evaluate the efficacy of using a long intestinal decompression tube(LT)in treatment of CD with acute intestinal obstruction.Methods:This is a prospective observational study.Comparative analysis was performed in CD patients treated with LT(the LT group)and nasogastric tube(the GT group).The primary outcome was the avoidance of emergent surgery.Additionally,predictive factors for failure of decompression and subsequent surgery were investigated.Results:There were 27 and 42 CD patients treated with LT and GT,respectively,in emergent situations.Twelve(44.4%)patients using LT were managed conservatively without laparotomy,while only nine(21.4%)patients in the GT group were spared from emergent surgery(P<0.05).Both in surgery-free and in surgery patients,the time to alleviation of symptoms was significantly shorter in the LT groups than in the GT groups(both P<0.01).C-reactive protein decrease after intubation and 48-hour drainage volume>500mL were predictors of unavoidable surgery(both P<0.05).The rate of temporary stoma and incidence of incision infection in the LT surgery group were significantly lower than those in the GT group(both P<0.05).No significant differences were observed in the frequency of medical and surgical recurrences between the LT and GT groups(all P>0.05).Conclusions:Endoscopic placement of LT could improve the emergent status in CD patients with acute bowel obstruction.The drainage output and changes in C-reactive protein after intubation could serve as practical predictive indices for subsequent surgery.Compared to traditional GT decompression,LT decompression was associated with fewer short-term complications and did not appear to affect long-term recurrence.展开更多
β-Carotene is one of the most abundant natural pigments in foods;however,usage of β-carotene is limited because of its instability.Microencapsulation techniques are usually applied to protect microencapsulated p-car...β-Carotene is one of the most abundant natural pigments in foods;however,usage of β-carotene is limited because of its instability.Microencapsulation techniques are usually applied to protect microencapsulated p-carotene from oxidization.In this study,β-carotene was microencapsulated using different drying processes:spray-drying,spray freeze-dryi ng,coati ng,and spray granulation.The properties of morphology,particle size,water con tent,thermal characteristic,and chemical stability have been explored and compared.Scanning electron microscopy measure?ments showed that the coated powder had a dense surface surro un ded by starch and suggested that the coati ng process gave a microencapsulated powder with the smallest bulk density and the best compressibility among the prepared powders.The chemical stabilities of microcapsules were evaluated during six months of storage at different temperatures.The coated powder had the highest mass fraction of β-carotene,which indicated that the coating process was superior to the three other drying processes.展开更多
基金supported by the Key R&D Program of Shandong Province of China(Grant number 2019QYTPY057)the Natural Science Foundation of Shandong Province of China(Grant numbers ZR2020ME110,ZR2021ME023)。
文摘This study focuses on finding a solution to the sharp decline in mechanical properties of Al-Si-Cu-Mg alloys due to rapid coarsening of traditional intermediate phases at high temperature.A new type of modified al oy,to be used in automobile engines at high temperatures,was prepared by adding Zr and Mo into Al-Si-Cu-Mg alloy.The synergistic effects of Zr and Mo on the microstructure evolution and high-temperature mechanical properties were studied.Results show that the addition of Zr and Mo generates a series of intermetallic phases dispersed in the alloy.They can improve the strength of the alloy by hindering dislocation movement and crack propagation.In addition,some nano-strengthened phases show coherent interfaces with the matrix and improve grain refinement.The addition of Mo greatly improves the heat resistance of the alloy.The extremely low diffusivity of Mo enables it to improve the thermal stability of the intermetallic phases,inhibit precipitation during aging,reduce the size of the precipitates,and improve the heat resistance of the alloy.
基金supported by the Natural Science Foundation of Shandong province(Grant No.ZR2021ME023)the Innovation Team Project of Jinan,China(Grant No.2019GXRC035)SQ project[2021370113124591]。
文摘The application of ultrasonic vibration during the casting process has been proven to refine the microstructure and enhance the properties of the casting.By using the direct inserting method,wherein the ultrasonic horn is inserted directly into the melt,ultrasonic treatment can be utilized in the semi-continuous casting process to produce aluminum ingots with simple shapes.However,due to the attenuation of ultrasound,it is challenging to apply the direct inserting method in the die casting process to produce complex castings.Thus,in this study,the impact of ultrasonic vibration on the microstructure of a gravity die-cast AlSi9Cu3end cap was investigated by applying ultrasonic vibration on the core(indirect method).It is found that the effect of ultrasonic vibration relies greatly on the resonance mode of the core.Selection of ultrasonic vibration schemes mainly depends on the core structure,and only a strong vibration can significantly refine the microstructure of the casting.For castings with complex structures,an elaborated ultrasonic vibration design is necessary to refine the microstructure of the specified casting.In addition,strong vibration applied on the feeding channel can promote the feeding ability of casting by breaking the dendrites during solidification,and consequently reduce the shrinkage porosity.
文摘AIM: To investigate the feasibility of compression anastomosis clip (CAC) for gastrointestinal anastomosis proximal to the ileocecal junction. METHODS: Sixty-six patients undergoing gastrointe-stinal anastomosis proximal to the ileocecal junction were randomized into two groups according to the anastomotic method, CAC or stapler. RESULTS: The postoperative recovery of patients in CAC and stapled anastomosis groups was similar. No postoperative complication related to the anastomotic method was found in either group. Both upper gastrointestinal contrast radiography at the early postoperative course and endoscopic examination after a 6-mo follow-up showed a better healing at the compression anastomosis. CONCLUSION: CAC can be used not only in colonic surgery but also in gastrointestinal anastomosis. Our result strongly suggests that CAC anastomosis is safe in various complication circumstances. However, it should be further conf irmed with a larger patient sample.
基金Project supported by the National Natural Science Foundation of China(Grant No.11675259)the West Light Foundation of the Chinese Academy of Sciences(Grant Nos.2016-QNXZ-B-8 and 2016-QNXZ-B-2)
文摘A pinned photodiode complementary metal–oxide–semiconductor transistor(CMOS) active pixel sensor is exposed to ^60Co to evaluate the performance for space applications. The sample is irradiated with a dose rate of 50 rad(SiO2)/s and a total dose of 100 krad(SiO2), and the photodiode is kept unbiased. The degradation of dark current, full well capacity,and quantum efficiency induced by the total ionizing dose damage effect are investigated. It is found that the dark current increases mainly from the shallow trench isolation(STI) surrounding the pinned photodiode. Further results suggests that the decreasing of full well capacity due to the increase in the density, is induced by the total ionizing dose(TID) effect, of the trap interface, which also leads to the degradation of quantum efficiency at shorter wavelengths.
文摘Objective To investigate whether asbestosis is a risk factor for mortality of lung cancer. Methods A fixed cohort study was established in an asbestos plant in Chongqing, China, and followed up for 30 years from the beginning of 1972. Basic personal information on life state, cause of death, and diagnosis of asbestosis was collected. Multiple logistic regressions were applied to analyze risk factors. Results During the 30-year follow-up, 584 male workers constituting a total of 14 664 person-years were monitored and data were analyzed. Among them, 203 (34.8%) died and the mortality rate was 13.8 per 1000 person-years, cancer accounting for 37.4%. Excess risks were observed for lung cancer (OR=3.72) and nonmalignant respiratory diseases (OR=2.73) among workers with asbestosis. High-exposure level was another risk factor for lung cancer (OR-3.20). Workers with category II of asbestosis demonstrated a higher OR of both lung cancer and nonmalignant respiratory diseases than those with category I of asbestosis. Conclusion High asbestos exposure level and asbestosis were the risk factors for death of lung cancer and nonmalignant respiratory diseases. Asbestosis is an independent risk factor for lung cancer among Chinese workers exposed to chrysotile, the risk increases with the increasing profusion of opacities of lung.
文摘Polycystic liver disease(PLD)is a rare hereditary disease that independently exists in isolated PLD,or as an accompanying symptom of autosomal dominant polycystic kidney disease and autosomal recessive polycystic kidney disease with complicated mechanisms.PLD currently lacks a unified diagnostic standard.The diagnosis of PLD is usually made when the number of hepatic cysts is more than 20.Gigot classification and Schnelldorfer classification are now commonly used to define severity in PLD.Most PLD patients have no clinical symptoms,and minority with severe complications need treatments.Somatostatin analogues,mammalian target of rapamycin inhibitor,ursodeoxycholic acid and vasopressin-2 receptor antagonist are the potentially effective medical therapies,while cyst aspiration and sclerosis,transcatheter arterial embolization,fenestration,hepatic resection and liver transplantation are the options of invasion therapies.However,the effectiveness of these therapies except liver transplantation are still uncertain.Furthermore,there is no unified strategy to treat PLD between medical centers at present.In order to better understand recent study progresses on PLD for clinical practice and obtain potential directions for future researches,this review mainly focuses on the recent progress in PLD classification,clinical manifestation,diagnosis and treatment.For information,we also provided medical treatment processes of PLD in our medical center.
基金supported by the Natural Science Foundation of Shandong province (ZR2021ME023)the Innovation Team Project of Jinan,China (2019GXRC035)
文摘The application of ultrasonic vibration to the casting process can be realized through mould(die)vibration.However,the resonant vibration of the mould is always accompanied by a non-uniform vibration distribution at different parts,which may induce a complex liquid flow and affect the casting fluidity during the mould filling process.The influence of non-uniform ultrasonic vibration on the fluidity of liquid AlSi9Cu3 alloy was studied by mould vibration with different vibration gradients.It is found that ultrasonic mould vibration can generate two opposite effects on the casting fluidity:the first,ultrasonic cavitation in melt induced by mould vibration promotes the casting fluidity;the second,the non-uniform mould vibration can induce a melt flow toward the weak vibration areas and turbulence there,consequently decreasing the casting fluidity.When the melt flow and turbulence are violent enough to offset the promoting effect of cavitation on fluidity,the ultrasonic vibration will finally induce a resultant decrease of casting fluidity.The decreasing effect is proportional to the vibration gradient.
文摘Objective:To explore the role of bone morphogenetic protein 4(BMP-4) in hepatic progenitor cells(HPCs).Methods:The effect of BMP-4 on rat hepatic oval cells was examined by using the WB-F344 rat hepatocytic epithelial stem-cell-like cell line.This hepatocytic cell line could exert various hepatocytc functions including the secretion of albumin and urea.Immunohistochemistry was used to examine the effects of BMP-4 and its antagonist,Noggin,on the proliferation and differentiation of these cells,cellular uptake and excretion of indocyanine green,the periodic acid-schiff(PAS) assay for glycogen storage and the expression of hepatic markers.Results:Our results showed for the first time that BMP-4 may acted as a potential inducer of hepatic differentiation in rat hepatic oval cells.Conclusions:This cell source offers a much-needed attractive and expandable source for future investigations of drug screening,stem cell technologies and cellular transplantation,in a society with increasing levels of liver disease and damage.
文摘Cholangiocarcinoma refers to malignant tumors that develop in epithelial lining of biliary system, and it is divided into two categories according to tumor location, intrahepatic cholangiocarcinoma (ICC) and extrahepatic cholangiocarcinoma (ECC). ICC occurs from the epithelial cells of the intrahepatic bile duct, its branches and interlobular biliary tree; and ECC is divided into hilar cholangiocarcinoma and distal cholangiocarcinoma by the circumscription at the confluence of cystic duct and the common hepatic duct.
基金Supported by Natural Science Foundation of Liaoning Province,No.20170541042
文摘BACKGROUND Papillary cystadenoma is a rare benign epithelial tumor of the salivary gland,which is characterized by papillary structures and oncocytic cells with rich eosinophilic cytoplasm. We found only one case of papillary cystadenoma in nearly 700 cases of salivary gland tumors. Our case was initially mistaken for a tumor of the right temporomandibular joint(TMJ) capsule rather than of parotid gland origin. Preoperative magnetic resonance imaging(MRI) and computed tomography(CT) should be carefully studied, which allows for appropriate preoperative counseling and operative planning.CASE SUMMARY Here, we report an unusual case of a 54-year-old woman with a parotid gland papillary cystadenoma(PGPC) that was misdiagnosed as a tumor of the right TMJ capsule. She was initially admitted to our hospital due to a mass anterior to her right ear inadvertently found 5 d ago. Preoperative CT and MRI revealed a well circumscribed tumor that was attached to the right TMJ capsule. The patient underwent a resection through an incision for TMJ, but evaluation of an intraoperative frozen section revealed a benign tumor of the parotid gland. Then we removed part of the parotid gland above the temporal facial trunk. The facial nerve was preserved. Postoperative histopathological findings revealed that the tumor was PGPC. No additional treatment was performed. There was no recurrence during a 20-mo follow-up period.CONCLUSION The integrity of the interstitial space around the condyle in MRI or CT should be carefully evaluated for parotid gland or TMJ tumors.
基金the China Postdoctoral Science Foundation under Grant No.2019M663467the National Natural Science Foundation of China under Grant No.62005037+2 种基金the Sichuan Science and Technology Program under Grant No.2020YJ0041the National Key Research and Development Program under Grant No.2019YFB2203400the“111 Project”under Grant No.B20030.
文摘Chiral metamaterial absorbers(CMMAs),a particular class of chiral metamaterials that refuse the transmission of incident radiation and exhibit different optical responses upon interactions with left and right circularly polarized(RCP)light,have gained research traction in recent years.CMMAs demonstrate numerous exotic and specialized applications owing to their achievable compatibility with various physical,chemical,and biomolecular systems.Aside from their well-evolved fabrication modalities for a broad range of frequencies,CMMAs exhibit strong chiroptical effects,making them central to various detection,imaging,and energy harvesting applications.Consequently,within the past decade,studies encompassing the design,optimization,and fabrication,as well as demonstrating the diverse applications of CMMAs have emerged.In this review,the theory,design,and fabrication of CMMAs are discussed,highlighting their top-down fabrication techniques as well as recent algorithmic and machine-learning(ML)-based approaches to the design and optimization.Some of their broad-spectrum applications are also discussed,spanning their roles in enantioselective photodetection,chiral imaging,generation of hot electrons,selective temperature sensing,and active chiral plasmonics.
基金Supported by the 345 Talent Project of Shengjing Hospitalthe Natural Science Foundation of Liaoning Province,No.20170541042.
文摘Malignant lymphoma originates from the lymphohematopoietic system.It can occur in any lymphoid tissue.Malignant lymphoma of the salivary gland is rare,but its incidence has increased in recent years.Its clinical-presentations are nonspecific,and it is often manifested as a painless mass in a salivary gland,which can be accompanied by multiple swollen cervical lymph nodes.Confirmation of the diagnosis before an invasive procedure is difficult.Clinically,malignant lymphoma of the salivary gland tends to be misdiagnosed,leading to an inappropriate treatment plan and the ultimate delay in the optimal treatment of the disease.This article reviews the pathogenesis,clinical features,imaging findings,diagnosis,treatment and prognosis of malignant lymphoma of the salivary gland.
基金Supported by 345 Talent Project of Shengjing HospitalNatural Science Foundation of Liaoning Province,No.20170541042.
文摘BACKGROUND Multiple intraoral dermoid cysts of large magnitude generally appear in the second or third decade of life.They are rare in infants and are usually solitary.In this case,a large mass was identified in utero during prenatal exams.CASE SUMMARY We introduce a rare case on multiple dermoid cysts in the floor of the mouth of an infant who underwent two surgeries for this.Preoperative magnetic resonance imaging confirmed a large well-circumscribed cystic lesion that originated at the former midline region in the floor of the mouth in which a suspicious lesion of minute size was likely compressed by the bulkier mass and overlooked.Therefore,the infant underwent two surgeries by an intraoral approach within 9 mo.At 5 mo after the second operation,a routine follow-up ultrasound showed evidence of an additional cyst.No further surgery was planned because the tumor had no immediate effect.CONCLUSION This report demonstrates the importance of carefully analyzing preoperative imaging to avoid multiple operations for a seemingly isolated oral cyst.
文摘BACKGROUND We report a case of essential thrombocythemia(ET)in a 44-year-old male who exhibited non-ST-segment-elevation myocardial infarction(NSTEMI)as the first manifestation without known cardiovascular risk factors(CVRFs).For the first time,we reported a left main trifurcation lesion in NSTEMI caused by ET,including continuous stenosis lesions from the left main to the ostial left anterior descending(LAD)artery and an obvious thrombotic lesion in the ostial and proximal left circumflex(LCX)artery.There was 60%diffuse stenosis in the left main(LM)that extended to the ostial LAD,thrombosis of the ostial LAD and proximal LCX,and 90%stenosis in the proximal LCX.During the operation,thrombus aspiration was performed,but no obvious thrombus was aspirated.Performing the kissing balloon technique(KBT)in the LCX and LM unexpectedly increased the narrowness of the LAD.Then,the single-stent crossover technique,final kissing balloon technique and proximal optimization technique(POT)were performed.On the second day after percutaneous coronary intervention(PCI),the number of platelets(PLTs)still increased significantly to as high as 696×10^(9)/L.The bone marrow biopsy done later,together with JAK2(exon 14)V617F mutation,confirms the diagnosis of ET.Hydroxyurea was administered to inhibit bone marrow proliferation to control the number of PLTs.CASE SUMMARY A 44-year-old male patient went to a local hospital for treatment for intermittent chest pain occurring over 8 h.The examination at the local hospital revealed elevated cTnI and significantly elevated platelet.Then,he was diagnosed with acute myocardial infarction and transferred to our hospital for emergency interventional treatment by ambulance.During the operation,thrombus aspiration,the single-stent crossover technique,final kissing balloon technique and POT were performed.Dual antiplatelet therapy comprising aspirin and ticagrelor was used after PCI.Evidence of mutated JAK2 V617F and bone marrow biopsy shown the onset of ET.Together with JAK2(exon 14)V617F mutation,ET was diagnosed according to the World Health Organization(WHO)diagnostic criteria,and the patient was placed on hydroxyurea.During the one-year postoperative period,repeated examinations showed a slight increase in PLTs,but the patient no longer had chest tightness,chest pain or bleeding or developed new thromboembolisms.CONCLUSION Routine physical examinations and screenings are conducive to the early detection of ET,and the risk for thrombosis should be assessed.Then,active antiplatelet therapy and myelosuppression therapy should be used for high-risk ET patients.
文摘Background:Enhanced recovery after surgery (ERAS) protocols or fast-track (FT) programs enable a shorter hospital stay and lower complication rate.Minimally invasive surgery (MIS) is associated with a lesser trauma and a quicker recovery in many elective abdominal surgeries.However,little is known of the safety and effectiveness made by ERAS protocols combined with MIS for gastric cancer.The purpose of this study was to evaluate the safety and effectiveness made by FT programs and MIS in combination or alone.Methods:We summarized an 11-year experience on gastric cancer patients undergoing elective laparotomy or minimally invasive gastric resection in standard cares (SC) or FT programs during January 2004 to December 2014.A total of 984 patients were enrolled and assigned into four groups:open gastrectomies (OG) with SC (OG + SC group,n =167);OG with FT programs (OG + FT group,n =277);laparoscopic gastrectomies (LG) with FT programs (LG + FT group,n =248);and robot-assisted gastrectomies (RG) with FT programs (RG + FT group,n =292).Patients&#39; data were collected to evaluate the clinical outcome.The primary end point was the length of postoperative hospital stay.Results:The OG + SC group showed the longest postoperative hospital stay (mean:12.3 days,median:11 days,interquartile range [IQR]:6-16 days),while OG + FT,LG + FT,and RG + FT groups recovered faster (mean:7.4,6.4,and 6.6 days,median:6,6,and 6 days,IQR:3-9,4-8,and 3-9 days,respectively,all P 〈 0.001).The postoperative rehabilitation parameters such as flatus time after surgery (4.7 ± 0.9,3.1 ± 0.8,3.0± 0.9,and 3.1 ± 0.9 days) followed the same manner.After 30 postoperative days&#39; follow-up,the total incidence of complications was 9.6% in OG + SC group,10.1% in OG + FT group,8.1% in LG + FT group,and 10.3% in RG + FT group.The complications showed no significant differences between the four groups (all P 〉 0.05).Conclusions:ERAS protocols alone could significantly bring fast recovery after surgery regardless of the surgical technique.MIS further reduces postoperative hospital stay.It is safe and effective to apply ERAS protocols combined with MIS for gastric cancer.
基金Supported by the Major Research plan of National Natural Science of China under Grant No.11790324the National Key Research and Development Program of China under Grant Nos.2016YY0200804 and 2017YFF0206205+1 种基金the National Magnetic Confinement Fusion Science Program of China under Grant Nos.2013GB106004 and 2012GB-101003the National Natural Science Foundation of China under No.1179320013
文摘In this paper, we develop a new path search algorithm which considers all the degrees of freedom and apply it on our calculated five-dimensional potential energy surface(PES) of^(236) U. Asymmetric and symmetric fission paths and barriers are obtained.
基金financially supported by the National Natural Science Foundation of China (No.51601102)the Natural Science Foundation of Shandong Province (No.ZR2016EEM48)the Key Research and Development Program Plan of Shandong Province (No.2018GGX103012)。
文摘To investigate the effect of yttrium(Y) on microstructure refinement and mechanical properties of aluminum alloy A356.2,the different trace contents of Y(0 wt%,0.025 wt%,0.050 wt%,0.075 wt%,or 0.100 wt%)were introduced into the liquid alloy.The alloys were fabricated in a preheated permanent mold,and subsequently treated by a T6 heat treatment.The results of tensile testing indicate that the yield strength(YS),the ultimate tensile strength(UTS) and the elongation(El) of the A356.2 alloy are improved by the Y additions.The YS dependence on grain size for the test alloys follows the Hall-Petch equation,which gives YS=-354.1+2875.2 d^(-1/2) with a correlation of R^(2)=0.83.As 0.050 wt%Y is added,the optimum values of the YS,UTS and El are achieved after T6 heat treatment.The secondary phases were identified by X-ray diffraction(XRD) which mainly consisted as Si,Mg2 Si and Al3 Y.The scanning electron microscope(SEM) and energy-dispersive spectrometer(EDS) analyses reveal the presence of the nano-sized Al3 Y particles on the surface of the Si phase.The A356.2 alloy with the Y addition is strengthened by the dendritic refinement,and the presence of the micron-and nano-sized Al3 Y precipitates.
基金supported by the Major Program of the National Natural Science Foundation of China under Grant No.11790324The National Magnetic Confinement Fusion Science Program of China under Grant Nos.2013GB106004 and 2012GB-101003The National Key Research and Development Program of China under Grant Nos.2016YY0200804 and 2017YFF0206205。
文摘Five-dimensional(5D)fission potential energy surfaces(PES)for uranium nuclei are investigated based on the macroscopic–microscopic Lublin–Strasbourg drop model in the threequadratic-surface parametrization,and the heights of static fission barriers are obtained.Asymmetric and symmetric fission paths are presented on the 5D PES of 236U for different nuclear shapes.The calculated barrier heights,EAand EB,are quite consistent with the experimental data for all even–even nuclei of uranium isotopes,from 230U to 244U.
基金This study was supported by the National Natural Science Foundation of China(81770556).
文摘Background:Conservative therapy for Crohn’s disease(CD)-related acute bowel obstruction is essential to avoid emergent surgery.The present study aimed to evaluate the efficacy of using a long intestinal decompression tube(LT)in treatment of CD with acute intestinal obstruction.Methods:This is a prospective observational study.Comparative analysis was performed in CD patients treated with LT(the LT group)and nasogastric tube(the GT group).The primary outcome was the avoidance of emergent surgery.Additionally,predictive factors for failure of decompression and subsequent surgery were investigated.Results:There were 27 and 42 CD patients treated with LT and GT,respectively,in emergent situations.Twelve(44.4%)patients using LT were managed conservatively without laparotomy,while only nine(21.4%)patients in the GT group were spared from emergent surgery(P<0.05).Both in surgery-free and in surgery patients,the time to alleviation of symptoms was significantly shorter in the LT groups than in the GT groups(both P<0.01).C-reactive protein decrease after intubation and 48-hour drainage volume>500mL were predictors of unavoidable surgery(both P<0.05).The rate of temporary stoma and incidence of incision infection in the LT surgery group were significantly lower than those in the GT group(both P<0.05).No significant differences were observed in the frequency of medical and surgical recurrences between the LT and GT groups(all P>0.05).Conclusions:Endoscopic placement of LT could improve the emergent status in CD patients with acute bowel obstruction.The drainage output and changes in C-reactive protein after intubation could serve as practical predictive indices for subsequent surgery.Compared to traditional GT decompression,LT decompression was associated with fewer short-term complications and did not appear to affect long-term recurrence.
基金Project supported by the Hubei Province Technology Innovation Project(No.2017ACA083),China
文摘β-Carotene is one of the most abundant natural pigments in foods;however,usage of β-carotene is limited because of its instability.Microencapsulation techniques are usually applied to protect microencapsulated p-carotene from oxidization.In this study,β-carotene was microencapsulated using different drying processes:spray-drying,spray freeze-dryi ng,coati ng,and spray granulation.The properties of morphology,particle size,water con tent,thermal characteristic,and chemical stability have been explored and compared.Scanning electron microscopy measure?ments showed that the coated powder had a dense surface surro un ded by starch and suggested that the coati ng process gave a microencapsulated powder with the smallest bulk density and the best compressibility among the prepared powders.The chemical stabilities of microcapsules were evaluated during six months of storage at different temperatures.The coated powder had the highest mass fraction of β-carotene,which indicated that the coating process was superior to the three other drying processes.