To address communication interference in complex noise environments inside and outside helmets,this study aims to improve the acoustic communication quality of in-helmet systems.A four-element microphone array communication hardware system was designed and implemented for use within the confined space of a helmet.Based on simulations of the internal acoustic field,the system incorporates a set of signal processing techniques,including array beamforming,echo cancellation,stationary noise speech enhancement,non-stationary noise suppression,and automatic gain control,forming a complete voice signal processing framework.Experimental results show that the proposed in-helmet microphone array noise reduction system achieves favorable downlink voice clarity under a total noise level of 85 dB(A),preliminarily validating the effectiveness and applicability of the implemented algorithms.This research provides essential technical and theoretical support for the future design and development of open-form in-helmet communication systems.

Aiming at the problem that the amount of Oxygen remaining and available time can not be accurately predicted while an astronaut conducting extravehicular activities(EVAs)in EVA spacesuit.Research the oxygen consumption process of EVA spacesuit.The model and algorithm of oxygen consumption are established by the gas state equation including compressibility and temperature coefficient,combined with human metabolism and micro leakage characteristics of spacesuit.Experimental data show that the orecast model and algorithm hasing high accuracy and practicability.

Objective:To understand the current situation of anxiety and depression in patients with atrial fibrillation who are going to undergo radiofrequency ablation and their family members and analyze the influencing factors.Methods:Using the convenient sampling method, a total of 197 patients with atrial fibrillation and their family members who were admitted to Arrhythmia Center of Beijing Anzhen Hospital Affiliated to Capital Medical University and planned to undergo radiofrequency ablation from October to December 2020 were selected as the research objects. The general information questionnaire, Generalized Anxiety Disorder (GAD-7) and Patient Health Questionaire-9 items (PHQ-9) were used to investigate them. Binomial logistic regression analysis was used to investigate the influencing factors of anxiety and depression in patients with atrial fibrillation who were going to undergo radiofrequency ablation and their family members.Results:The PHQ-9 score of 197 patients with atrial fibrillation undergoing radiofrequency ablation was (3.9±3.8) , the GAD-7 score was (2.7±3.1) , the detection rate of depressive symptom was 34.5% (68/197) and the detection rate of anxiety symptom was 20.3% (40/197) . The PHQ-9 score of family members of patients was (1.9±3.0) , the GAD-7 score was (1.8±2.9) , the detection rate of anxiety symptom was 15.2% (30/197) and the detection rate of depressive symptoms was 16.2% (32/197) . Binomial Logistic regression analysis showed that the number of attacks in the past 1 month was greater than or equal to 4 times and the duration of atrial fibrillation episodes in the past 1 month was greater than or equal to 6 hours as the influencing factors of depressive symptoms ( P<0.05) . The number of seizures more than or equal to 4 in the past month was the influencing factor of anxiety symptoms of patients ( P<0.05) . The anxiety state of patients was the influencing factor of anxiety symptoms of family members ( P<0.05) . Conclusions:The current situation of anxiety and depression in patients with atrial fibrillation who are going to undergo radiofrequency ablation and their family members is not optimistic. The recent frequent attack of atrial fibrillation is the influencing factor of anxiety and depression symptoms of patients and the anxiety state of patients is the influencing factor of anxiety symptoms of family members. Medical staff should also pay attention to the anxiety and depression of patients with atrial fibrillation who are going to undergo radiofrequency ablation and their family members and give effective interventions as soon as possible.

It is necessary to use objective and accurate methods to assess the changes of the consciousness of patients emergencing from general anesthesia. In this way, adverse medications during the waking period can be avoided, and it can ensure the stable and safe recovery of consciousness of the patients, quickly remove the adverse factors affecting the patients, and strive to reduce the occurrence of complications during the waking period. This article briefly reviews the research progress of bispectral index and other common clinical anesthesia depth monitoring techniques used to assess the changes of consciousness of patients awakening from general anesthesia, and explores the regular pattern of recovery of consciousness in patients awakening from general anesthesia, in order to reduce complications in the recovery period .

Since December 2019, the corona virus disease 2019 (COVID-19) caused by the 2019 novel coronavirus (2019-nCoV) has been reported in Wuhan, Hubei Province. Almost 70% of patients susceptible to 2019-nCoV are over age of 50 years, with extremely large proportion of critical illness and death of the elderly patients. Meanwhile, the elderly patients are at high risk of osteoporotic fractures especially osteoporotic vertebral compression fractures (OVCF). During the prevention and control of COVID-19 epidemic, orthopedists are confronted with the following difficulties including how to screen and protect OVCF patients, how to accurately diagnose and assess the condition of OVCF patients with suspected or confirmed COVID-19, and how to develop reasonable treatment plans and comprehensive protective measures in emergency and outpatient clinics. In order to standardize the diagnosis and treatment of patients with OVCF diagnosed with COVID-19, the authors jointly develop this expert consensus. The consensus systematically recommends the standardized emergency and outpatient screening and confirmation procedures for OVCF patients with suspected or confirmed COVID-19 and protective measures for emergency and outpatient clinics. Moreover, the consensus describes the grading and classification of OVCF patients diagnosed with COVID-19 according to the severity of illness and recommends different treatment plans and corresponding protective measures based on the different types and epidemic prevention and control requirements.

Gastric schwannoma is a tumor originating from mesenchymal tissue. The clinical incidence is relatively rare, accounting for 6.3% of all gastric stromal tumors. The tumor is more likely to occur in the body of the stomach and usually originates from the gastric submucosal nerve. Most gastric schwannomas do not have any clinical symptoms. Imaging examination can play a diagnostic role, but the diagnosis still requires pathological examination, especially S-100 protein which is the gold standard for the diagnosis of gastric schwannomas. Gastric schwannoma usually needs to be distinguished from gastrointestinal stromal tumors and gastrointestinal autonomic nerve tumors. In terms of treatment, complete surgical resection is the first choice.

Objective To document the impact of conversion to mycophenolate mofetil (MMF)at different time points after transplantation on the renal function of renal function.Methods A longterm,multicenter,non-interventional and observational study was done.Two cohorts were included:One was Switch cohort (340 cases) including renal allograft recipients who switched to MMF at least 6 months after renal transplantation and followed up for 4 years after switch; The other was Stay cohort (123 cases),including renal allograft recipients who received MMF treatment after transplantation and followed up for 4 years after enrollment.Results GFR values of patients in Switch cohort was significantly increased after switch,and the change in GFR slope was 3.1 mL· min-1 · year-1 (P＜0.01).GFR values of patients in Stay cohort kept steady before and after enrollment,and the change in GFR slope was 0.44 mL·min-1 ·year-1 (P＞0.05).Statistically significant difference in the onset time of GFR decline (defined as 20％ decline from the baseline) was observed among subgroups within Switch cohort (P＜0.01),but there was no significant difference among subgroups within Stay cohort (P＞0.05).Stay cohort was 12％ higher than in Switch cohort every year.Conclusion Conversion to MMF ＞6 months or even many years after transplantation can obviously improve the renal function of recipients.The earlier conversion can benefit improvement of the renal function.

Marine Actinobacteria are emerging as new resources for bioactive natural products with promise in novel drug discovery. In recent years, the richness and diversity of marine Actinobacteria from the South China Sea and their ability in producing bioactive products have been investigated. The objective of this work is to isolate and identify bioactive secondary metabolites from a marine actinobacterium SCSIO 1934 derived from sediments of South China Sea. The strain was identified as a Streptomyces spieces by analyzing its 16S rDNA sequence. Streptomyces sp. SCSIO 1934 was fermented under optimized conditions and seven bioactive secondary metabolites were isolated and purified by chromatographic methods including colum chromatography over silica gel and Sephadex LH-20. Their structures were elucidated as 17-O-demethylgeldanamycin (1), lebstatin (2), 17-O-demethyllebstatin (3), nigericin (4), nigericin sodium salt (5), abierixin (6), respectively, by detailed NMR spectroscopic data (1H, 13C, COSY, HSQC and HMBC). This work provided a new marine actinobacterium Streptomyces sp. SCSIO 1934, capable of producing diverse bioactive natural products.
Anti-Bacterial Agents ; chemistry ; China ; DNA, Ribosomal ; chemistry ; genetics ; Geologic Sediments ; microbiology ; Oceans and Seas ; RNA, Ribosomal, 16S ; genetics ; Streptomyces ; chemistry ; classification ; genetics ; isolation & purification

Objecttve To compare the positional and volumetric differences of planning target volumes(PTVs)based on axial three-dimensional CT(3D-CT)and four-dimensional CT(4D-CT)for the primary tumor of non-small cell lung cancer(NSCLC).Methods Sixteen NSCLC patients with lesions located in the upper lobe and 12 patients with lesions in middle and lower lobes,totally 28 patients, initially underwent three-dimensional CT scans followed by 4D-CT scans of the thorax under normal free breathing.PTVvector was defined on gross tumor volume (GTV) contoured on 3D-CT and its motion vector. The clinical target volumes(CTVs)were created by adding 7 mm to GTVs,then, internal target volume (ITVs)were produced by enlarging CTVs isotropically based on the individually measured amount of motion in the 4D-CT,lastly,PTVs were created by adding 3 mm setup margin to ITVs. PTV4D was defined on the fusion of CTVs on all phases of the 4D data.The CTV wag generated by adding7 mm to the GTV on each phase.then,PIVs were produced by fusing CTVs on 10 phases and adding 3 mm setup margin.The position of the target center,the volume of target and the degree of inclusion(DI)were compared reciprocally between the PTVvector and the PTV 4D The difference of the position,volume and degree of inclusion of the targets between PTVvecter and PTV4D were compared,and the relevance between the relative characters of the targets and the three-dimensional vector was analyzed based on the groups of the patients. Results The median of the 3 D motion vector for the lesions in the upper lobe was 2.8 mm, significantly lower than that for the lesions in the middle and lower lobe ( 7.0 mm, z = - 3. 485, P < 0. 05 ). In the upper lobe group there was only significant spatial difference between the PTVvector and PTV4D targets in the center coordinate at the x axe (z = -2. 010, P < 0. 05 ), while in the middle and lower lobes there was only significant spatial difference between the PTVvector and PTV4D targets in the center coordinates at the z axe (z = -2. 136,P <0.05). The median of ratio of PTV4D and PTVvector, of the upper lobe group was 0. 75, significantly higher than that of the middle and lower lobes group (0. 52, z = - 2. 949, P < 0. 05 ).A significant correlation was found for the motion vector and the ratio of PTV and PTV4D in both groups ( r = - 0. 638, - 0. 850, P < 0. 05 ). For all patients, the median of D[ of PTV4D in PTVvector was 66. 39% ,while the median of DI of PTVvector, in PTV4D was 99. 55% , both showed a positive significant correlation with the motion vector (r = -0. 814,0. 613 ,P < 0. 05). Conclusions PTV4D defined based on 4D-CT simulation images is obviously less than PTV defined based on 3D-CT simulation images. The ratio and DI of both targets are related with the three-dimensional motion vector of the tumor.

Objective To compare positional and volumetric differences of internal gross tumor volume (IGTV) delineated separately by three approaches based on four-dimensional CT (4DCT) for the primary tumor of non-small cell lung cancer (NLCLC). Methods Twenty-one patients with NLCLC underwent big bore 4DCT simulation scan of the thorax. IGTVs of the primary tumor of NSCLC were tumor on the MIP images were delineated to produce IGTVMIP. The position of the target center, the volume of target, the degree of inclusion (DI) and the matching index (MI) were compared reciprocally between IGTV10, IGTVEI+EE and IGTVMIP. Results Average differences between the position of the center of IGTVs on direction of x,y and z axes were less than 1 mm, with no statistically significant difference. The volume of IGTV10 was larger than that of IGTVEI+EE, the difference was statistically significant (t=2.37,P=0.028);the volume of IGTV10 was larger than that of IGTVMIP, but the difference was not statistically significant(t=1.95 ,P=0.065). The ratio of IGTVEI+EE with IGTV10, IGTVMIP with IGTV10 were 0.85±0.08 and 0.92±0.11, respectively. DI of IGTVEI+EE in IGTV10, IGTVMIP in IGTV10 were 84.78% ± 8. 95% and 88.47% ±9.04%. MI between IGTV10 and IGTVEI+EE, IGTV10 and IGTVMIP were 0.85 ±0.09, 0.86±0. 09, respectively. Conclusions The center displacement of the IGTVs delineated separately by the three different techniques based on 4DCT images are not obvious; IGTVEI+EE and IGTVMIP can not replace IGTV10 , however , IGTVMIP is more close to IGTV10 comparing to IGTVEI+EE . The ratio of GTVEI+EE with IGTV10 is correlated to the tumor motion vector. As the vector increases, the ratio of GTVEI+EE with IGTV10decreases, especially for small tumors.