Study on the dynamic response and roadways stability during mining under the disturbance of hard roof break.

Under the condition that the working face was directly covered with hard roof, the abrupt breaking of hard roof release significant amount of energy, thus prone to triggering dynamic disasters such as roadway instability or rockburst. This paper based on the engineering background of the Xieqiao Coal Mine's 11,618 working face, a numerical simulation method was put forward to study the dynamic response of roadway under the disturbance of hard roof breaking and proposed an evaluation index IC for roadway stability. Research indicates that the elastic energy released during the periodic weighting of the hard roof is higher than that released during the first weighting. Under the dynamic disturbance caused by hard roof breaking, the peak stresses of the roadway was slight decreased, accompanied by a significant increase in the range of stress concentration and plastic zone expansion. Roadway deformation patterns are significantly influenced by hard roof breaking, with noticeable increases in deformation on the roof and right side. During the period of hard roof breaking, the possibility of instability of the roadway increase significantly due to the disturbance caused by the dynamic load. The research results reveal the instability mechanism of roadway under the condition of hard roof, and provide a more reliable basis for evaluating the stability of roadway.

Clinical study on modified Topping-off technology in the treatment of multiple lumbar degenerative diseases / 中国骨伤

OBJECTIVE@#To explore the clinical effect of the modified Topping-off technique in the treatment of multiple lumbar degenerative diseases.@*METHODS@#From October 2019 to May 2020, 42 patients who underwent modified Topping-off operation (modified Topping-off group) and 42 patients who underwent multilevel total laminectomy and interbody fusion with screw rod system internal fixation (whole laminectomy group) were observed and analyzed. There were 15 males and 27 females in the modified Topping-off group, aged from 28 to 80 years old, with an average of (59.57±11.85)years old. There were 14 males and 28 females in the whole laminectomy group, aged from 45 to 82 years old, with an average of (64.26±9.19) years old. Visual analogue scale (VAS) and Oswestry Disability Index (ODI) were evaluated before operation, 1 week, 6 weeks and 12 weeks after operation. The intraoperative blood loss, incision length, operation time, postoperative drainage, weight-bearing time, hospitalization time, intervertebral space height, intervertebral foramen height and lumbar mobility were statistically analyzed.@*RESULTS@#All patients were followed up for 12 weeks. The intraoperative blood loss and postoperative drainage in the modified Topping-off group were significantly less than those in the whole lamina group (P<0.05). The incision length, operation time, weight-bearing time and hospital stay in the modified Topping-off group were shorter than those in the whole lamina group(P<0.05). There were significant differences in intervertebral space height, intervertebral foramen height and lumbar mobility between the two groups at 12 weeks after operation(P<0.05). The modified Topping-off group had significantly lower VAS 1, 6, 12 weeks after operation and ODI 12 weeks after operation compared with rhose before operation. The VAS at 1, 6, 12 weeks in the whole lamina group were significantly lower those that before operation(P<0.05). The ODI at 12 weeks in the whole lamina group were significantly lower than those before operation(P<0.01). There were significant differences in VAS scores between the two groups at 1 week, 6 weeks and 12 weeks after operation(P<0.01). There was significant difference in ODI between the two groups 12 weeks after operation(P<0.01).@*CONCLUSION@#The application of modified Topping-off technique in the treatment of multi segmental lumbar degenerative diseases can reduce the total length of fusion segments, avoid or slow down the degeneration of adjacent segments, and has a positive effect on maintaining the normal movement of the spine.

Emergence of SARS-CoV-2 through Recombination and Strong Purifying Selection

COVID-19 has become a global pandemic caused by a novel coronavirus SARS-CoV-2. Understanding the origins of SARS-CoV-2 is critical for deterring future zoonosis and for drug discovery and vaccine development. We show evidence of strong purifying selection around the receptor binding motif (RBM) in the spike gene and in other genes among bat, pangolin and human coronaviruses, indicating similar strong evolutionary constraints in different host species. We also demonstrate that SARS-CoV-2s entire RBM was introduced through recombination with coronaviruses from pangolins, possibly a critical step in the evolution of SARS-CoV-2s ability to infect humans. Similar purifying selection in different host species and frequent recombination among coronaviruses suggest a common evolutionary mechanism that could lead to new emerging human coronaviruses. One Sentence SummaryExtensive Recombination and Strong Purifying Selection among coronaviruses from different hosts facilitate the emergence of SARS-CoV-2

Determination of six polyphenols in different parts of Queshe tea extracted by different processes by HPLC / 中草药

Objective: To establish HPLC method for the determination of 6'-O-caffeoylarbutin (1), arbutin (2), robustaside A (3), p-hydroxybenzoic acid (4), caffeic acid (5) and caffeic acid methyl ester (6) of Queshe tea. Methods: Using the SunFire® C18 (250 mm×4.6 mm, 5 μm) chromatographic column, mobile phase of acetonitrile-0.1% phosphoric acid aqueous solution, the flow rate at 1.0 mL/min, and column temperature at 30 ℃ to optimum the extraction method of Queshe tea and investigate the linearity, stability and repeatability of the method. Results: With distilled water as the extraction solvent, the highest extraction rate can be obtained by ultrasonic extraction for 20 min. Under the above chromatographic conditions, 6'-O-caffeoylarbutin (1), arbutin (2), robustaside A (3), p-hydroxybenzoic acid (4), caffeic acid (5) and caffeic acid methyl ester (6) have good separation effect, and the experiment has good linearity, stability and repeatability. Conclusion: The method is simple, sensitive and accurate, and can be used for the detection of the above six main chemical components.

Study on Quality Standard of Sanyuan Rupixiao Gel Paste / 中国中医药信息杂志

Objective To establish the quality standard for Sanyuan Rupixiao Gel Paste. Methods Sparganii Rhizoma, Gleditsiae Sinensis Fructus, Cyperi Rhizoma and Impatientis Semen were identified by TLC method. The content of tetrahydropalmatine was determined by HPLC. Waters symmetry column was used with the mobile phase of acetonitrile-0.1% phosphatic acid in a gradient manner (pH was adjusted to 6.4 by triethylamine) (55:45) at the detection wavelength of 280 nm. The flow rate was 1.0 mL/min at the column temperature of 30 ℃. Results The spots in TLC were clear without any interference;tetrahydropalmatine showed a good linear relation in the range of 0.092–1.84 μg;the average recovery was 100.15%with RSD of 1.58%(n=6). Conclusion The method is simple and accurate with high reproducibility, which can be used for the quality control of Sanyuan Rupixiao Gel Paste.

The value of DWI for the diagnosis of ovarian lesions / 实用放射学杂志

Objective To investigate the diagnostic value of diffusion-weighted imaging (DWI) in ovarian cystic or solid lesions with different b values.Methods 95 patients,total 105 lesions,including 61 benign lesions (53 cystic,19 solid) and 33 malignant lesions (10cystic,23 solid) with ovarian cystic or solid lesions underwent traditional MRI and DWI.The scan sequence of DWI was SE-EPI,with the b values of 0,500,1 000 s/mm2.The contrast to noise ratio (CNR) was calculated to evaluate the image quality.The apparent diffusion coefficient (ADC) value and exponent apparent diffusion coefficient (eADC) value of ovarian masses were measured.Results With the increase of b values,the signal and CNR of ovarian masses was decreased,and the intensity of cystic component was sharper than that of solid component.There was no signifi cant difference of the ADC values and eADC values between the benign and malignant ovarian cystic masses (P＞0.05).But the results had significant difference between the benign and malignant ovarian solid masses (P＜0.05).Conclusion Quantitative analysis of ADC and analysis the characteristic of CNR will help the differential diagnosis of some benign and malignant ovarian diseases.

CT Findings of Chronic Hepatic Schistosomiasis and Its Complications / 昆明医科大学学报

Objective To analyze the CT characteristics of chronic schistosomiasis liver disease,in order to improve the accuracy of CT diagnosis for the disease.Methods We analyzed the CT features of 125 cases of clinical pathology diagnosis of chronic schistosomiasis liver and of 50 normal control group,and measured the hepatic lobe lines and spleen index.Results (1) Schistosoma calcification:In 125 cases,there were 120 patients with varying degrees of liver calcification,in which 76 cases of intrahepatic or subcapsularlinear calcification,44 cases of reticular or map-like calcification,33 cases of calcification portal system,15 cases of spleen calcification,85 cases of intestinal wall calcification;(2) Morphological changes of the liver and spleen:The transverse diameter of the left hepatic lobe,caudate lobe,and caudate lobe-right lobe ratio were larger in patients with chronic schistosomiasis than controls,the transverse diameter of the right hepatic lobe were smaller and there were statistically difference (P＜0.001).There were 82 cases of expanded gallbladder fossa in chronic schistosomiasis.Splenic index in patients with chronic schistosomiasis and had no obvious difference in the control group (P＞0.05);(3) Schistosomiasis liver's complications:there were 43 cases of cholecystitis and cholelithiasis,11 cases of liver cancer,5 cases of colon cancer,3 cases of bladder cancer.Conclusion Intrahepatic calcification and the left hepatic lobe and caudate lobe enlargement are CT signs of chronic schistosomiasis,which is often merged with many complications.

Post-expansile hydrogel foam aerosol of PG-liposomes: a novel delivery system for vaginal drug delivery applications.

The purpose of this work was to develop and characterize a novel delivery system of post-expansile hydrogel foam aerosol of propylene glycol-embodying liposomes (PG-liposomes) (PEHFL) for vaginal drug delivery applications. Matrine (MT) was used as a model drug to investigate the vaginal mucous membrane permeation behavior of MT from PEHFL versus PG-liposomes foam aerosol (PLFA), hydrogel foam aerosol (HFA) and hydrogel (HYG). The MT loaded PG-liposomes were characterized for shape, particle size, polydispersity, zeta potential and encapsulation efficiency; the foams of PEHFL were also characterized for swelling behavior, mucoadhesive force and duration. Results revealed that: (i) the MT loaded PG-liposomes had a mean size of 122 ± 16 nm, a good polydispersity index of 0.147 ± 0.023, and exhibited a negative charge of -47.5 ± 0.4 mV, the MT entrapment capacity in PG-liposomes (was calculated as percentages of total drug) was 80.8 ± 2.6%; (ii) the foams of PEHFL had a laggingly swelling process after spurted from a sealed container, and the higher the temperature of the surrounding environment, the greater the degree of swelling, this swelling state of foams would greatly enhance drug spread uniformly in vaginal canal and contact the vaginal walls tightly; (iii) the foams of PEHFL had a mucoadhesive force about 1460 ± 123 mN/cm(2), and could sustain 85 ± 11 min in vitro; (iv) the overall mean permeated MT through unit mass of porcine vaginal tissue from PEHFL was 2.64, 2.34 and 7.59 times higher than that from PLFA, HFA and HYG, respectively (t-test, P<0.05); and the quantity of MT remaining in the vaginal tissue at the end of the 12h experiment was also significantly greater (t-test, P<0.05) from the PEHFL than from PLFA, HFA and HYG. All of these results indicate that the main advantages of PEHFL over conventional dosage forms are the ability to enhance the vaginal mucosa permeability of MT, spread uniformly in vaginal canal especially the highly folded epithelial surfaces, prolong the residence time at the site of administration and induce MT delayed release. In conclusion, the PEHFL may be a promising delivery system for vaginal delivery of medication.

Mitochondrial respiratory chain complex I deficiency due to 10191T>C mutation in ND3 gene / 中国当代儿科杂志

This study reviews a case of mitochondrial respiratory chain complex I deficiency due to the 10191T>C mutation in mitochondrial ND3 gene. The previously healthy boy progressively presented with blepharoptosis, weakness, epilepsy and motor regression at age 6 years. Elevated blood lactate and pyruvate were observed. Brain magnetic resonance imaging showed symmetrical lesions in the basal ganglia. Leigh syndrome was thus confirmed. The protein from the mitochondria and genomic DNA of the boy and his parents was collected from peripheral blood leucocytes for the activity test for mitochondrial complex I to V and genetic analysis. The results showed the activity of complex I (33.1 nmol /min in 1 milligram mitochondrial protein) was lower than normal reference value (44.0±5.4 nmol /min in 1 milligram mitochondrial protein). The ratio of complex I to citrate synthase (19.8%) was also lower than normal reference value (48%±11%). The activities of complexes II to V were normal. 10191T>C mutation in ND3 gene of mitochondria was identified in the boy. 10191T>C mutation and complex I deficiency were not detected in his parents. At present, he is 16 years old, and of normal intelligence with spastic paralysis in both lower extremities after treatment. It is concluded that a Chinese boy with isolated complex I deficiency due to 10191T>C mutation in ND3 gene was firstly diagnosed by peripheral leukocytes mitochondrial respiratory chain enzyme assay and gene analysis. This study can provide clinical data for the nosogenesis of Leigh syndrome.

Achievements and challenges of the World Bank Loan/Department for International Development grant-assisted Tuberculosis Control Project in China / 中华医学杂志(英文版)

In March 2002, the government of China launched the World Bank Loan/ Department for International Development-supported Tuberculosis (TB) Control Project to reduce the prevalence and mortality of TB. The project generated promising results in policy development, strengthening of TB control systems, patient treatment success, funds management, and the introduction of legislation. In light of the global TB epidemic and control environment, it is useful to review the TB control priorities of the project, summarize the achievements and experiences around its implementation.

A case of Leigh syndrome associated with respiratory chain complex I deficiency due to mitochondrial gene 13513G>A mutation / 中国当代儿科杂志

Leigh syndrome is a genetically heterogeneous disease caused by defects in enzymes involved in aerobic energy metabolism and the Krebs', cycle. Mitonchondrial complex I deficiency is a main cause of Leigh syndrome. In this study, a Chinese child with Leigh syndrome caused by 13513G>A mutation was reported. The proband was the first child of his parents. The previously healthy boy presented with generalized epilepsy at 12 years of age. When he visited Peking University First Hospital at 13 years of age, he had subacute loss of vision in two eyes and temporal defect of visual field in the left eye. He walked with a spastic gait. His blood lactate and pyruvate levels were elevated. Muscle biopsy showed mild lipid accumulation in muscle fiber. An electrocardiogram showed incomplete right bundle branch block. Brain magnetic resonance imaging showed bilateral, symmetrical lesions in the basal ganglia, supporting the diagnosis of Leigh syndrome. 13513G>A mutation was identified by gene analysis in the patient, which led to mitochondrial respiratory chain complex I deficiency. Multivitamins and L-carnitine were administered. At present, the patient is 16 years old and has progressive deterioration with significant muscle weakness and body weight loss. He is absent from school. He has no obvious retardation in intelligence. 13513G>A mutation was first identified by gene analysis in Chinese population with Leigh syndrome. This may be helpful in genetic counseling.

Inhibitory effect of angiogenesis inhibitor TNP-470 on human ACHN renal cell carcinoma / 华中科技大学学报（医学）（英德文版）

The contribution of angiogenesis inhibitor TNP-470 to the growth and metastasis of ACHN renal cell carcinoma (RCC) was studied. TNP-470 (40 mg/kg, every two days) was administrated to BABL/c nude mice bearing ACHN RCC. The mice were sacrificed after a treatment duration of 31 days and the weight and volume of subcutaneous tumors as well as foci of lung metastasis were measured. The microvascular density (MVD) of the tumor as well as the PCNA index and apoptotic index of the tumor cells were evaluated immunohistochemically. Result showed that the growth of ACHN RCC was suppressed significantly and none metastasis was observed in TNP-470-treated mice. Compared with the control group, the MVD was decreased markedly (P < 0.01) and the apoptotic index was increased significantly (P < 0.01) in the treated group. The tumor volume was positively correlated to the MVD (r = 0.7144, P < 0.01) and inversely correlated to the apoptotic index (r = -0.8607, P < 0.01), and MVD was conversely correlated to the apoptotic index. It was determined that TNP-470 could effectively inhibit angiogenesis of ACHN RCC, which resulting in ischemia and hypoxia, leading to increased apoptosis, thus obviously suppressing the growth and metastasis of ACHN RCC in nude mice.

Effects of HIF-2? and VEGF on Angiogenesis and Metastasis of Renal Cell Carcinoma / 中国医师杂志

Objective To explore the expression of HIF-2? and VEGF in renal cell carcinoma (RCC) and their correlation with angiogenesis and metastasis of renal cell carcinoma. Methods Expression of HIF-2? and VEGF were assessed by immunohistochemical straining in 48 cases of renal cell carcinomas. Results In 48 cases of renal cell carcinomas, positive rate of HIF-2? was 70.8%. Strong expression of HIF-2? was observed in 12 cases, moderate in 10 cases, weak in 12 cases and no expression in 14cases.There was a significant difference in HIF-2? expression between carcinoma tissues and control tissues (P