ABSTRACT
Objective To investigate the effect from circumferential distribution angle of forwards wedge vortex generators on aerodynamic drag reduction during flow around a cylinder, so as to provide theoretical evidences for low drag sprint garment design. Methods Forwards wedge vortex generators were reconstructed based on the NIKE’s AeroBalde. Given that the individual parts of an athlete body can be treated as multiple cylinders with varied dimensions and positions, 48 forwards wedge vortex generators were distributed as four columns on windward side of the cylinder, which were symmetrical with the YOZ plane. When the air flowed through the cylinder at the speed of 32 km/h, large eddy simulation was carried out on the computational domains which were properly meshed with polyhedral mesh to investigate the drag force, flow filed and pressure distributions. Results It was effective for drag reduction of the cylinder induced by airflow when two columns of forwards wedge vortex generators were circumferential distributed in the range of 55°-75°and the circumferential internal angle between two columns was in the range of 10° or 15°. The pressure distribution on leeward side of the cylinder was apparently changed after surface modification, which minimized the pressure drag dominant in aerodynamic drag. The drag reduction mechanism was that micro-vortices were generated downstream after flow through the forwards wedge vortex generators, which resulted in an early transition to critical flow with low drag force. Conclusions Effective aerodynamic drag reduction is achieved if forwards wedge vortex generators are properly distributed. The research findings can provide guidance for wind tunnel test and low drag sprint garment design.
ABSTRACT
Sports biomechanics is an interdisciplinary application science that studies human movement. The main purpose of sports biomechanical research is to improve competitive sports performance and prevent sports injuries. This review introduced methods commonly used in biomechanical research, and selected results in biomechanical research on sports performance, training method and sports equipment, so as to provide references for improving the quality of biomechanical research in China. It is hoped that more biomechanical studies will be conducted with the focus on sports performance improvement and injury prevention, using rigorous research design and new technologies to obtain more accurate biomechanical data in human movement, so as to increase the breadth and depth of sports biomechanical researches.
ABSTRACT
Head and neck squamous cell carcinoma (HNSCC) is the most common pathological type in head and neck tumor. It can evade immune response through various mechanisms such as immune tolerance, immune escape, high expression of immune checkpoint molecules in tumor cells and T cell signal destruction. In recent years, immune checkpoint inhibitor therapy has made a breakthrough in HNSCC patients. From second-line therapy to first-line therapy in recurrent and metastatic HNSCC, then adjuvant therapy in locally advanced HNSCC patients, several clinical studies of immune checkpoint inhibitors (ICIs) therapy have been showed good therapeutic effects. In addition, a variety of combination therapies such as ICI combination with targeted therapy, ICI, radiotherapy and other methods currently being studied. However, the beneficiaries of immune checkpoint inhibitors are still unclear, and how to effectively combine immune checkpoint inhibitors with chemotherapy, radiotherapy, targeted therapy and surgery is currently being explored. In the period of individualized treatment, the treatment strategies for HNSCC are experiencing new changes, facing more options and challenges. In this article, we will review some major clinical studies of immune checkpoint inhibitor therapy in squamous cell carcinoma of the head and neck in recent years.
ABSTRACT
Objective:To explore the effect of laparoscopic surgery on postoperative rehabilitation and stress response of patients with colorectal cancer.Methods:From January 2018 to September 2019, 94 patients with colorectal cancer were selected in the General Hospital of Marine Police of the Chinese People's Armed Police Force.They were divided into observation group (47 cases) and control group (47 cases) according to the random digital table method.The observation group was treated with laparoscopic surgery, while the control group was treated with open surgery.The changes of perioperative indicators, postoperative rehabilitation indicators, postoperative complications and 24-hour stress response indicators were compared between the two groups.Results:The time of lymph node dissection and operation had no statistically significant differences between the two groups (all P>0.05). The amount of bleeding of the observation group [(153.61±27.58)mL] was less than that of the control group [(271.32±23.25)mL] ( t=22.371, P<0.05). In the observation group, the exhaust time [(43.27±6.18)h] and the recovery time of bowel sounds [(20.31±3.28)h] were faster than those in the control group [(67.38±9.91)h and (34.54±5.17)h] ( t=14.153, 15.934, all P<0.05). The incidence of postoperative complications in the observation group (4.26%) was lower than that in the control group (21.28%) (χ 2=6.114, P<0.05). The serum levels of norepinephrine (NE) [(92.13±10.45)μg/L], C-reactive protein (CRP) [(17.38±3.01)mg/L] and Cor [(137.87±23.15)μg/L] in the observation group were lower than those in the control group [(136.27±15.42)μg/L, (26.73±2.34)mg/L and (185.42±27.39)μg/L] ( t=16.245, 16.813, 9.090, all P<0.05). Conclusion:Laparoscopic radical resection of colorectal cancer has good effect on patients with colorectal cancer.It can speed up postoperative rehabilitation and reduce stress response.It is worthy of popularizing.
ABSTRACT
Objective To study the effects of cinobufotalin capsule combined with transcatheter arterial chemoembolization in patients with hepatocellular carcinoma.Methods 68 patients with hepatocellular carcinoma from January,2013 to March,2016 were selected and divided into the combination group and chemotherapy group according to the random number table method,each with 34 cases.The combination group was treated with transcatheter arterial chemoembolization and hepatic artery infusion chemotherapy embolization.The levels of D-dimer,tumor markers,clinical efficacy and quality of life scores were observed before and after treatment in 68 patients.Results There was no significant difference in plasma fibrinogen(FIB)in combination group before and after treatment.Before treatment,the levels of FIB)was similar to chemotherapy group.After treatment,the FIB content in the chemotherapy group was significantly higher than before treatment and that in the combination group the differences were statistically significant(P<0.05).After treatment,the levels of cytokeratin 19,carcinoembryonic antigen and neuron-specific enolase in two group were significantly higher than those before treatment(P<0.05).But there was no significant difference between the two groups after treatment.The rate of disease control in the combination group was significantly higher than that in the chemotherapy group(77.5％vs.65.4％,P<0.05).Cases of diarrhea and insomnia in chemotherapy group were similar to the combination group,but the differences of cases of pain and fatigue between two group were statistically significant(P<0.05).Conclusion Cinobufotalin capsule combined with transcatheter arterial chemoembolization can improve the hypercoagulability of the patient's blood,and is beneficial to the treatment of cancer,improve the disease control rate and improve the life of patients.
ABSTRACT
BACKGROUND:Transplantation of mesenchymal stem cels to prevent and treat degeneration of the intervertebral disc is a feasible method. Mesenchymal stem cels co-transfected by SRY-related high mobility group-box gene 9 (SOX-9) and growth differentiation factor-5 (GDF-5) can differentiate into nucleus pulposus cels, in order to obtain greater effect of induction and proliferation of nucleus pulposus cels. OBJECTIVE:To investigate the effect of SOX-9 and GDF-5 co-transfection on the differentiation of rabbit bone marrow mesenchymal stem cels into nucleus pulposus cels. METHODS: We separated and cultured bone marrow mesenchymal stem cels from the bone marrow of rabbit aged 4 months. Passage 3 cels were divided into five groups andin vitro induced to differentiate into nucleus pulposus cels: non-transfected group, empty vector transfection group, SOX-9 transfection group, GDF-5 transfection group, SOX-9 and GDF-5 co-transfection group. At 14 days after transfection, RT-PCR was employed to assay SOX-9, GDF-5 and colagen type II mRNA expressions in bone marrow mesenchymal stem cels. The marker of nucleus pulposus cels-KRT19 expression was also detected by immunohistochemical staining. RESULTS AND CONCLUSION:In the co-transfection group, the mRNA expressions of SOX-9, GDF-5, and colagen type II were significantly higher than those in the SOX-9 transfection group, GDF-5 transfection group, and both these two groups, respectively (P < 0.05). Cels were positive for KRT19 in the SOX-9 and GDF-5 groups, and strongly positive for KRT19 in the co-transfection group. These findings indicate that double gene-transfected bone marrow mesenchymal stem cels are better than single gene-transfected cels with regard to differentiation into nucleus pulposus cels and secretion of extracelular matrix.
ABSTRACT
BACKGROUND:Intervertebral disc can bear load but lack vessels. Nucleus pulposus cel s have the problem of phenotype loss during in vitro culture that can lead to degenerative changes. The mechanism of intervertebral disc degeneration remains unclear. OBJECTIVE:To explore the approaches of isolation, adherence culture, amplification and identification of the rabbit nucleus pulposus cel s in vitro, to observe the growth characteristics of nucleus pulposus cel s in different generations. METHODS:Type Ⅱ col agenase digestion method plus explants culture method was used to isolate and purify nucleus pulposus cel s and then amplify in vitro. The morphology and growth of primary and passaged cel s was observed under the inverted microscope, the number of cel s was counted and the growth curve was draw. The morphology of the cel s was observed under light microscope after hematoxylin-eosin staining, and the expressions of col agen type Ⅱ and aggrecan were examined by immunocytochemistry. RESULTS AND CONCLUSION:Nucleus pulposus cel s of rabbit were isolated, cultured and amplified in vitro successful y. Growth activity was observed, and found that the 1-3 generation nucleus pulposus cel s proliferated more rapidly and vigorously. The proliferation of nucleus pulposus cel s was decreased while the cel passaged more generations. These isolated and cultured nucleus pulposus cel s could positively express the col agen type Ⅱ and aggrecan. In vitro combination of type Ⅱ col agenase digestion method and explants culture method could obtain high purity nucleus pulposus cel s, and the cultured nucleus pulposus cel s were grew in round or polygonal. The 1-3 generation of cel s had strong activity.
ABSTRACT
Objective To explore the function and clinical effect of automatic nerve retractor in micro-endoscopic discectomy.Methods From August 2009 to December 2010,350 patients with lumbar disc hemiation were treated by micro-endoscopic discectomy,including 196 males and 154 females,aged from 17 to 68 years (average,42 years).Three cases were at L1-2,8 at L2-3,12 at L3-4,186 at L4-5 and 141 at L5S1.The automatic nerve retractor was used in all micro-endoscopic discectomy.The visual analogue scale (VAS) and Oswestry disability index (ODI) were used to evaluate clinical outcomes.Results All patients were followed up for 6 to 16 months (average,9 months).The mean VAS score decreased from preoperative 8.79±1.15 to 3.80±1.14 3 months after operation and 3.65±1.14 6 months after operation.The mean ODI score decreased from preoperative 78％±1.71％ to 28％±1.72％ 3 months after operation and 28％±1.88％ 6 months after operation.Postoperative VAS and ODI scores decreased significantly compared with those before operation.The VAS and ODI scores 6 months after operation were not significantly improved compared with those 3 months after operation.No spinal cord and nerve root injury and epidural hematoma formation occurred in all cases.Conclusion In micro-endoscopic discectomy,the automatic nerve retractor can help the operator obtain effective exposure,protect nerves from injury,alleviate workload of the operators,therefore it has a great clinical application value.
ABSTRACT
Objective To evaluate the imaging features of benign fibrous histiocytoma (BFH).Methods Imaging data were retrospectively collected and reviewed in 11 patients with pathologically proved BFH.Of the 11 patients,X-ray was performed in all patients,MR scans in 6 patients,and CT scans in 4 patients.Results ALL lesions detected were a solitary lesion.The distribution of BFH was in the tibia (n =5 ),femur ( n =3),fibula ( n =1 ),sacrum ( n =1 ),and thoracic vertebrae ( n =1 ).X-ray features included eccentric osteolytic lesions in 7 patients and centric in 2 patients,with clear boundary and thinning of the cortex,and 7 patients with varying degrees of ossified border were found. CT scan shows bone destruction with density similar to soft tissue.The majority of lesions ( n =3 ) were observed in the expanding shell of bone,2 patients in the tibia and 1 patient in the thoracic lesions with cortical bone perforation.The thoracic lesion as soft tissue mass was detected. All of the lesions detected in CT showed no periosteal reaction.In patients with MR images,hypo to isointense signal intensity on T1WI and hyperintense signal intensity on T2WI was found. All lesions on post-contrast T1WI were detected with homogeneous or heterogeneous lesion with moderate or significant enhancement.Conclusion Imaging features were typical for MFH which is useful tool helping correct diagnosis of MFH.
ABSTRACT
Objective To observe the imaging features of primary lymphoma of bone (PLB) on MRI and PET, and to assess the value of MRI combined with PET for PLB. Methods Sixteen patients with pathologically confirmed PLB were collected, and the MRI and PET appearances were analyzed retrospectively. Results Single bone infiltration was detected in 15 patients (5 in femurs, 3 in vertebro, 3 in right iliums, 2 in tibias, 1 in radius and 1 in maxillae), while multiple bones infiltration were noticed in 1 patient (lesion located in manubrium sterni and the 7th right rib). MRI demonstrated heterogeneous focal-lamellar or diffuse signal intensity within marrow, isointense or hypointense on T1WI and slightly hyperintense on T2WI with homogeneous or heterogeneous enhancement. Severe soft tissue mass was seen in all 16 patients, the range of soft tissue mass was larger than osseous lesion in 15 patients and equal to osseous lesion in 1. Most PLB were homogeneous isointense or slightly hypointense on T1WI and homogeneous or heterogeneous slight-hyperintense on T2WI with slightly or moderately homogeneous or heterogeneous enhancement, while in 3 patients showed single vertebral compression fracture with local epidural- and/or paravertebral-soft tissue, and the range of soft tissue larger than the pathologic vertebrae. PET was performed before operation in 13 patients, showing local increasement of glycometabolism and uptake of radioactive nuclide without abnormality for other sites. For three patients of primary lymphoma of vertebrae underwent PET after operation, and recurrence was detected in 1 patient after 2 months. Conclusion Large soft mass with small osseous destruction and relatively hypointensity on T2WI is somehow characteristic for PLB. PET features of PLB are not specific, but has some advantages in determining the nature of lesion, differentiating lesions and follow-up after operation. MRI combined with PET is an appropriate imaging method for PLB.
ABSTRACT
<p><b>OBJECTIVE</b>To observe the effect of Congrong powder preparation on erythrocyte parameter and the index of blood rheology in healthy rats.</p><p><b>METHOD</b>The 50 rats were randomly divided into 5 groups ( physiological saline group, testosterone propionate group, large-dose administered group, moderate-dose administered group, small-dose administered group). Blood were taken to determine erythrocyte parameter and the index of blood rheology.</p><p><b>RESULT</b>Congrong powder preparation had no effect on erythrocyte parameter. There was an increase in whole blood viscosity, whole blood reduction viscosity, and in the erythrocyte rigidity index in the large-dose administered group.</p><p><b>CONCLUSION</b>Congrong powder can influence deformability and some related characters of erythrocytes.</p>
Subject(s)
Animals , Male , Rats , Blood Viscosity , Drugs, Chinese Herbal , Pharmacology , Erythrocyte Deformability , Erythrocytes , Powders , Pharmacology , Random Allocation , Rats, WistarABSTRACT
point (P<0.05).Conclusion Transplantation of MBMCs promotes the expression of VEGF, up-regulates the MVD value in the acute injury livers, and facilitates the recovery of liver function.
ABSTRACT
Objective Our previous study demonstrated that toll-like receptor 2(TLR2) can distinguish extraneous antigen and prevent the immunological response. This study was designed to detect the expression of toll-like receptor 2 (TLR2) mRNA in cornea and investigate the effect of steroid on TLR2 expression in rats cornea following allograft penetrating keratoplasty. Methods The penetrating keratoplasty models were established in SPF rats with the 108 SD rats as receiptors and 36 SPF Wistar rats as donors, and other 6 SPF SD rats worked as normal controls. The receiptor rats were divided randomly into autograft group, allograft group and steriod group. The clarity and neovascularization of corneas of experiment rats were examined under the slit-lamp microscope and the rejection index was calculated based on Holland criteria. Corneal histopathological examination was carried out by hemotoxylin and eosin staining under the light microscope, and real time-PCR was employed for the detect of TLR2 mRNA in the corneas at the fifth, seventh and ninth day after operation. The experimental animals were obtained from the Animal Experimental Center of Southern Medical University and the procedure followed the Statement of Association for Research in Vision and Ophthalmology. Results The rejection occurred in 7 days after operation in allograft group, and only mild edema, opacity and neovascularization of corneas were found at different degrees in 9 days after operation in autograft group and steriod group. Severe corneal edema, a lots of inflammatory cells infiltration and new vessels in stroma were seen in allograft group, and mild inflammatory response was found in autograft group and steriod group. Normal comeal structure was exhibited in normal control group under the light microscope. The fold differences of TLR2 mRNA expression in cornea after amplification was significantly different among three groups and different time points (F_(group) = 39. 46, P = 0. 00; F_(time) =35. 38, P = 0. 00 ; F_(interaction) = 45. 66, P =0. 00), and the evident enhance of TLR2 mRNA expression was revealed in allograft group compared with autograft group (P ＜ 0. 05) and declined in steriod group (P ＜ 0. 05). Conclusion Steriod may restrain the acute allograft rejection by down-regulating the expression of TLR2 in corneas and its signals transaction. This result suggests that steriod offer a protection from rejection of cornea after penetrating keratoplasty.
ABSTRACT
Objective To explore the CT and MR imaging features of nodular fasciitis(NF), which will in return improve the standard and quality of diagnosis. Methods CT (n = 4) and MRI (n = 5) findings of pathologically proved nodular fasciitis in 9 patients were retrospectively analyzed. Results Of 9 NF, 5 were located in the lower extremities, 2 in the abdominal wall, and the others in the acoustic duct. The resected tumor size vary from 1.1 to 9. 5 cm in the largest diameter and mean (3.7±0.3) cm. All lesions appeared as a discrete solid mass on imaging. The CT value of lesions was similar to muscle. MR imaging manifested as a hypo to isointense lesion on T_1WI and hyperintense signal intensity on T_2WI. There was homogeneous or heterogeneous moderate to significant enhancement in the lesions. Conclusion CT and MRI can provide helpful information for the clinical and differential diagnosis of NF.
ABSTRACT
Objective To describe the CT and MR imaging features of hepatic inflammatory myofibroblastic tumor(IMT).Methods The CT(n=12)and MRI(n=2)findings of pathologically proved hepatic IMT in 12 patients were retrospectively analyzed.Results All the tumors of the 12 patients were solitary and located in right hepatic lobe.Six tumors were solid and 4 tumors were solid-cystic.The other 2 tumors were periportal soft-tissue infiltration.The tumors appeared as solid or solid-cystic hypodense mass on CT images.The lesions were dark in T1-weighted sequences and slightly bright on T2-weighted sequences.There was homogeneous or inhomogeneous moderate to significant enhancement in solid portion of the tumors.Honeycomb-like enhancement was demontrated both in the peripheral part and at the intratumoral septa of the solid-cystic mass.Conclusion CT and MRI can provide helpful information for the clinical diagnosis and differential diagnosis of hepatic IMT.
ABSTRACT
Aim To select the ideal experimental rats model for research on prevention and treatment of Hyperlipidemia.Methods Five prescriptions on experimental hyperlipidemia-rats were selected and emulsion was made.At 10、20、30 d blood samples were taken from ocular orbit and content of CHO、 LDL、 HDL 、TG in the serum were measured.Results Four of the five prescriptions could lead to the disorder of lipid metabolism at different levels.Conclusion An ideal experimental rats model of hyperlipidemia can be made if bile salt and propylthiouracil are conbined to add to the fat emulsion of lard and cholesterol.
ABSTRACT
The notational DSA was first proposed for the application as a managing tool of neuronradiology in the early 70's of 20th centery.Later on,three dimensional image reconstruction(3D DSA) was aquired along with the progressing development of technique and equipment devices.As a rather practical instrument,it has been utilized successfully in the diagnosis and management of head and neck vascular disorders,and abdominal parenchymal diseases during recent years.We comprehensively intoduce the application of rotational DSA for the diagnosis and management in hepatic diseases.