[Comparative study of ultrasound and magnetic resonance imaging in the diagnosis of asymptomatic anterosuperior acetabular labrum tears].

OBJECTIVE: To explore the diagnostic value of ultrasound for asymptomatic anterosuperior acetabular labral tears (ALT). METHODS: From August 2018 to February 2020, a total of 64 asymptomatic volunteers (101 hips) were recruited to complete 3.0T magnetic resonance imaging (MRI) and ultrasound examination. Among these asymptomatic volunteers, 31 were male and 33 were female, with the median age 35 (32, 39) years. Using 3.0T MRI findings as golden standard, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of ultrasound were calculated. RESULTS: The results showed the presence of unilateral or bilateral ALT in 33 (51.56%) asymptomatic vo-lunteers with a total of 47 hips (46.53%). Of the 37 asymptomatic volunteers with bilateral hip MRI examination, 14 had bilateral ALT and 8 had unilateral ALT. Of the 27 asymptomatic volunteers who underwent unilateral hip MRI, 11 had ALT. Of the 33 asymptomatic volunteers with labral tears, 11 were male and 22 were female, with 30 right hips and 17 left hips. The median age was 36 (33, 40) years in the ALT group and 34 (32, 38) years in the non-ALT group. There was no significant difference in age between the two groups (P > 0.05). In the asymptomatic population, the abnormal anterosuperior acetabular labrum manifestations on ultrasound were intra-labrum cleft in 26 cases, labral heterogeneous echogenicity in 25 cases, paralabral cysts in 2 cases, and labral focal hyperechoic area in 12 cases. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy for ALT diagnosed by ultrasound were 73.53%, 67.16%, 53.19%, 83.33% and 69.31%, respectively. The cross- sectional area (CSA) of the anterosuperior acetabular labrum was 0.20 (0.15, 0.24) cm2 in this study. The labral median CSA of the ALT group and non-ALT group were 0.22 (0.17, 0.28) cm2 and 0.17 (0.14, 0.21) cm2, respectively, with a statistically significant difference (P < 0.001). CONCLUSION: The ALT are common findings in asymptomatic volunteers on MRI. Intra-labrum cleft and labral heterogeneous echogenicity are common ultrasonographic signs in asymptomatic volunteers with ALT. The labra were more swollen in the asymptomatic volunteers with ALT compared to those without ALT.

[Definition of severe pulmonary tuberculosis: a scoping review].

Objective: To clarify the definition of severe pulmonary tuberculosis and its inclusion criteria by summarizing and analyzing the studies of severe pulmonary tuberculosis (TB). Methods: A systematic search of Medline (via PubMed), Cochrane Library, Web of Science, Web of Science, Epistemonikos, Embase, CNKI, WanFang database, and CBM database was conducted to collect studies published between 2017 and 2022 on patients with severe pulmonary TB. Searches were performed using a combination of subject terms and free words. The search terms included: tuberculosis, severe, serious, intensive care, critical care, respiratory failure, mechanical ventilation, hospitalization, respiratory distress syndrome, multiple organ failure, pulmonary heart disease, and pneumothorax. The definitions and inclusion criteria for severe pulmonary TB in the included studies were extracted. Results: A total of 19 981 studies were identified and 100 studies were finally included, involving 8 309 patients with severe pulmonary TB. A total of 8 (8.00%) studies explicitly mentioned the definition of severe pulmonary TB, and 53 (53.00%) studies clearly defined the inclusion criteria for patients with severe pulmonary TB. A total of 5 definitions and 30 inclusion criteria were extracted. A total of 132 dichotomous variables and 113 continuous variables were included in the outcome indicators related to patients with severe pulmonary TB of concern in the studies. Conclusions: The definition and diagnostic criteria for severe TB are unclear, and there is an urgent need to develop a clear definition and diagnostic criteria to guide clinical practice.

[SWOT analysis and strategy research for the training of doctoral candidate in general practice in China].

General practice has entered a stage of rapid development, but the doctoral postgraduate as the reserve strength of discipline development, its cultivation is still at the exploration stage. Through analyzing the internal strengths (S), internal weakness (W), external opportunities (O), and external threats (T) faced by the Ph.D. student in general practice in training, this paper discusses feasible strategies and plans for the cultivation of general practice to help the cultivation of high-level talents.

Magnetotransport in Graphene/Pb0.24Sn0.76Te Heterostructures: Finding a Way to Avoid Catastrophe.

While heterostructures are ubiquitous tools enabling new physics and device functionalities, the palette of available materials has never been richer. Combinations of two emerging material classes, two-dimensional materials and topological materials, are particularly promising because of the wide range of possible permutations that are easily accessible. Individually, both graphene and Pb1-xSnxTe (PST) are widely investigated for spintronic applications because graphene's high carrier mobility and PST's topologically protected surface states are attractive platforms for spin transport. Here, we combine monolayer graphene with PST and demonstrate a hybrid system with properties enhanced relative to the constituent parts. Using magnetotransport measurements, we find carrier mobilities up to 20 000 cm2/(V s) and a magnetoresistance approaching 100%, greater than either material prior to stacking. We also establish that there are two distinct transport channels and determine a lower bound on the spin relaxation time of 4.5 ps. The results can be explained using the polar catastrophe model, whereby a high mobility interface state results from a reconfiguration of charge due to a polar/nonpolar interface interaction. Our results suggest that proximity induced interface states with hybrid properties can be added to the still growing list of behaviors in these materials.

[Clinical characteristics of 272 437 patients with different histopathological subtypes of primary esophageal malignant tumors].

Objective: To characterize the histopathological subtypes and their clinicopathological parameters of gender and onset age by common, rare and sparse primary esophageal malignant tumors (PEMT). Methods: A total of 272 437 patients with PEMT were enrolled in this study, and all of the patients were received radical surgery. The clinicopathological information of the patients was obtained from the database established by the State Key Laboratory of Esophageal Cancer Prevention & Treatment from September 1973 to December 2020, which included the clinical treatment, pathological diagnosis and follow-up information of esophagus and gastric cardia cancers. All patients were diagnosed and classified by the criteria of esophageal tumor histopathological diagnosis and classification (2019) of the World Health Organization (WHO). The esophageal tumors, which were not included in the WHO classification, were analyzed separately according to the postoperative pathological diagnosis. The χ2 test was performed by the SPSS 25.0 software on count data, and the test standard α=0.05. Results: A total of 32 histopathological types were identified in the enrolled PEMT patients, of which 10 subtypes were not included in the WHO classification. According to the frequency, PEMT were divided into common (esophageal squamous cell carcinoma, ESCC, accounting for 97.1%), rare (esophageal adenocarcinoma, EAC, accounting for 2.3%) and sparse (mainly esophageal small cell carcinoma, malignant melanoma, etc., accounting for 0.6%). All the common, rare, and sparse types occurred predominantly in male patients, and the gender difference of rare type was most significant (EAC, male∶ female, 2.67∶1), followed with common type (ESCC, male∶ female, 1.78∶1) and sparse type (male∶ female, 1.71∶1). The common type (ESCC) mainly occurred in the middle thoracic segment (65.2%), while the rare type (EAC) mainly occurred in the lower thoracic segment (56.8%). Among the sparse type, malignant melanoma and malignant fibrous histiocytoma were both predominantly located in the lower thoracic segment (51.7%, 66.7%), and the others were mainly in the middle thoracic segment. Conclusion: ESCC is the most common type among the 32 histopathological types of PEMT, followed by EAC as the rare type, and esophageal small cell carcinoma and malignant melanoma as the major sparse type, and all of which are mainly occur in male patients. The common type of ESCC mainly occur in the middle thoracic segment, while the rare type of EAC mainly in the lower thoracic segment. The mainly sparse type of malignant melanoma and malignant fibrous histiocytoma predominately occur in the lower thoracic segment, and the remaining sparse types mainly occur in the middle thoracic segment.

[Clinical analysis of penetrating keratoplasty for infants with congenital corneal opacity].

Objective: To investigate the corneal graft survival and related risk factors of primary penetrating keratoplasty in congenital corneal opacity infants. Methods: It was a retrospective cohort study. Data were collected from forty-two infants (51 eyes) who were aged ≤12 months and diagnosed with congenital corneal opacity in Beijing Tongren Hospital and Beijing Anzhen Hospital from January 1, 2017 to January 31, 2018. The mean age at surgery was (5.7±2.2) months (3-12 months). The mean follow-up duration was (28.6±2.6) months (24-33 months). All the patients underwent penetrating keratoplasty. The status of the corneal grafts and complications were observed and recorded during the regular follow-up. The survival probabilities were estimated by using the Kaplan-Meier and Log-rank test. The graft survival between different influence factors was analyzed by using the χ2 test. Results: The Kaplan-Meier survival rates for penetrating keratoplasty were 84.3% (43/51) at 6 months, 78.4% (40/51) at 12 months and 60.8% (31/51) at the last follow-up. The presence of corneal neovascularization was significantly correlated with graft failure (χ²=5.264, P=0.022). The graft survival differed between eyes receiving combined surgery and mere penetrating keratoplasty and in eyes with varied surgical indications (P=0.039, <0.01). Increased intraocular pressure (7 eyes, 13.7%) and persistent epithelial defects (7 eyes, 13.7%) were the most common postoperative complications, followed by complicated cataract (4 eyes, 7.8%) and posterior capsule opacification (2 eyes, 3.9%). Conclusions: The graft survival rate was satisfactory following pediatric keratoplasty although it had a tendency to decrease with the follow-up time. Corneal neovascularization was a major risk factor of graft failure. Surgical indications and procedures also had a certain effect on the graft survival.

Dietary Fiber and All-Cause and Cardiovascular Mortality in Older Adults with Hypertension: A Cohort Study Of NHANES.

OBJECTIVES: Several studies have documented that dietary fiber was inversely associated with a variety of diseases, but the association of dietary fiber with the prognosis of older adults with hypertension is unknown. The aim was to assess the association of dietary fiber with all-cause and cardiovascular mortality in older adults with hypertension. METHODS: This study enrolled 4906 participants (51.6% were female) aged 65 years or older with hypertension in the National Health and Nutrition Examination Survey (NHANES) 2003-2014 and ascertained mortality through December 31, 2015. Dietary fiber intake data were assessed by using a 24-h recall survey. Participants were grouped by dietary fiber intake quartiles: Q1(fiber < 10.20, g/day), Q2 (10.20 ≤ fiber < 14.45, g/day), Q3 (14.45 ≤ fiber < 19.85, g/day), and Q4 (19.85 ≤ fiber, g/day). Multivariate Cox proportional hazard models were used to evaluate the associations of dietary fiber intake with all-cause and cardiovascular mortality. Kaplan-Meier survival curves and restricted cubic spline models were applied to reveal the relationship between dietary fiber intake and mortality. RESULTS: Over the median follow-up duration of 70 months (interquartile range: 38-100 months), 1369 participants were determined as all-cause mortality (27.9%) and 270 participants were identified as cardiovascular mortality (5.5%). In the fully adjusted model, the higher dietary fiber intake group was associated with relatively lower all-cause (Q4 vs Q1: 0.68 (0.58, 0.80); P for trend <0.001) and cardiovascular mortality (Q4 vs Q1: 0.64 (0.45, 0.92); P for trend =0.010). The non-linear relationship was not observed between dietary fiber intake and all-cause or cardiovascular mortality. CONCLUSIONS: Higher dietary fiber intake was significantly associated with decreased all-cause and cardiovascular mortality in older adults with hypertension. Increasing dietary fiber intake may improve the prognosis of older adults with hypertension.

[Accuracy of photogrammetry and conventional impression techniques for complete-arch implant rehabilitation: an in vitro comparative study].

Objective: To compare the accuracy of photogrammetry and conventional impression techniques for complete-arch implant rehabilitation. Methods: An edentulous maxillary stone cast containing 8 screw-retained implant abutment replicas was derived from a 74-year-old male patient who visited the Department of Dental Implant Center, Capital Medical University School of Stomatology in September 2019. The stone cast was copied through the open-tray splinted impression, and the copied cast was used as the master cast for this study. The abutment-level impressions of master cast were made by photogrammetry (PG) and the conventional impression technique (CNV) by one attending doctor. Group PG: after which scan bodies were connected to each implant replica, a photogrammetry system was used to obtain digital impressions of the master cast (n=10); Group CNV: conventional open-tray splinted impression technique was performed to fabricate conventional definitive casts (n=10). After connecting the scan bodies onto each implant replicas, the master cast and the 10 definitive casts from group CNV were digitized with a laboratory reference scanner. All data of group PG, group CNV and mater cast were saved as ".stl" files. For all test scans and reference scan, the three-dimensional information of scan bodies were converted to implant abutment replicas using a computer aided design software (Exocad). The data of the group PG and the group CNV were respectively registered with the reference data (trueness analysis) and pairwise within group (precision analysis) for accuracy evaluation in a three-dimensional analysis software (Geomagic Control X). Results: The trueness and precision of group PG [(17.33±0.34) and (2.50±0.79) µm ] were significantly statistically better than those of group CNV [(24.30±4.16) and (26.12±4.54) µm] respectively (t=-5.29 and -34.35, P<0.001). Conclusions: For complete-arch implant abutment-level impression, photogrammetry produces significantly better accuracy than conventional impression technique.

[Application of metagenomic next-generation sequencing technology in pathogen detection in patients with burns and patients with acute or chronic wounds].

Objective: To explore the value of using metagenomic next-generation sequencing (mNGS) technology to detect pathogens in patients with burns and patients with acute or chronic wounds. Methods: A retrospective observational study was conducted. From March 2019 to June 2020, 11 patients with burns and patients with acute or chronic wounds (including 10 males and 1 female, aged 23 to 85 years) in the Fourth Medical Center of PLA General Hospital met the inclusion criteria and were recruited. A total of 23 specimens were collected, including 6 whole blood specimens, 1 skin tissue specimen, 1 drained pus specimen, and 15 wound secretion swab specimens. Each specimen was divided into two parts, which were subjected for pathogen detection using microbial culture method and mNGS method, respectively. The number and types of pathogens detected by the 2 methods and the relative abundance detected by the mNGS method were recorded, and the consistency of the two methods were compared. Data were statistically analyzed with paired Wilcoxon rank sum test. Results: With the microbial culture method, no pathogen was detected in 5 of the 23 specimens, while 35 pathogens were detected in the remaining 18 specimens, belonging to 9 species of bacteria and 2 species of fungi. Five specimens had one pathogen while 9 specimens had 2 pathogens and 4 specimens had 3 pathogens detected in each specimen. With the mNGS method, no pathogen was detected in one of the 23 specimens, while 75 pathogens were detected in the remaining 22 specimens, belonging to 28 species of bacteria, 3 species of fungi, and 3 species of viruses. Eight specimens had one pathogen, 5 specimens had 2 pathogens, 2 specimens had 3 pathogens, 3 specimens had 4 pathogens, 2 specimens had 6 pathogens, and 1 specimen had 7 pathogens, and 1 specimen had 20 pathogens detected in each specimen. The number of pathogens detected in each specimen by microbial culture method was 2 (1, 2) types, which was significantly less than 2 (1, 4) types by mNGS method (Z=3.359, P<0.01). In 5 specimens, no bacteria were detected by microbial culture method but mNGS method detected bacteria in 2 specimens and virus in 2 different specimens. The mNGS method detected two or more types of bacteria in 13 specimens, the relative abundance of bacteria with the 1st relative abundance ranking ranged from 28.8% to 95.9% in each specimen. Of the 23 specimens detected by two detection methods, 7 specimens (30.4%) showed identical detection results, 5 specimens (21.7%) showed totally different detection results, and 11 specimens (47.8%) had partially consistent detection results. Conclusions: Compared with the traditional microbial culture method, the mNGS method has higher detection sensitivity and stronger capacity to detect pathogens, and can determine the relative abundance of pathogens in mixed infections. As a supplement to the culture method, the mNGS method is expected to play an important role in the diagnosis of infectious pathogens in burns and acute or chronic wounds.

Comparison of clinical diagnostic value of spiral CT with different dose in patients with early-stage peripheral lung cancer.

PURPOSE: To compare the clinical diagnostic value of spiral CT scan with different dose in patients with early-stage peripheral lung cancer. METHODS: A total of 163 cases of patients with early-stage peripheral lung cancer who came to People's Hospital of Rizhao for treatment from June 2014 to January 2017 were retrospectively analyzed. A total of 78 cases of patients who received low-dose CT scanning were the low-dose group, another 84 cases of patients who received routine dose CT scanning were the routine dose group. Multislice helical CT (MSCT) scanning was performed in both groups, with tube voltage of 120 kV. Tube current was 25 m A in the low-dose group and 250 m A in the routine dose group. In addition, a total of 80 patients with lobar pneumonia were added as the control group of diagnostic sensitivity, specificity and accuracy. Pathological diagnosis was taken as the gold standard to compare the diagnostic sensitivity, specificity and accuracy of the two groups. RESULTS: The image quality, nodules and signs of the two groups were compared, and the results of radiation dose of the two groups were compared. The diagnostic sensitivity, specificity and accuracy of the low-dose group were 82.05%, 87.50% and 84.81%, respectively. The diagnostic sensitivity, specificity and accuracy of the routine dose group were 85.71%, 86.25% and 85.97%, respectively. The diagnostic value of the two groups was not statistically significant (p > 0.05). However, the radiation dose in the low-dose group was significantly lower than that in the routine group. CONCLUSION: Low-dose MSCT scanning can meet the clinical requirements for imaging diagnosis of peripheral lung cancer, and can reduce the radiation dose of patients.

Evaluation of the correlation between myocardial fibrosis and ejection fraction in dilated cardiomyopathy using magnetic resonance T1 mapping.

OBJECTIVE: The study aimed to evaluate the correlation between myocardial fibrosis and ejection fraction (EF) in dilated cardiomyopathy (DCM) by magnetic resonance T1 mapping. PATIENTS AND METHODS: For this study, 48 patients with DCM and 24 healthy volunteers from 2015 to 2017 were included. All participants were examined by 3.0T cardiovascular magnetic resonance (CMR), and T1 mapping images were obtained using the MOLLI sequence. MATLAB software was used to extract the histogram parameters of the T1 mapping images, including five groups of percentiles, kurtosis coefficient, skewness coefficient, variance, and mean. The EF value was calculated based on short-axis cine cardiac images, and a Pearson's coefficient between T1 mapping parameters and the EF value was calculated. RESULTS: The T1 mapping histogram parameters, such as the mean, variance, maximum, and 10, 25, 50, 75, and 90 percentiles of DCM patients were significantly higher than those of the controls. The differences were statistically significant (p < 0.05). The EF of DCM patients was significantly lower than that of the controls, and the difference was statistically significant (p < 0.05). The T1 mapping parameters, such as the mean, variance, maximum, and percentiles, were significantly negatively correlated with EF. CONCLUSIONS: T1 mapping is helpful in diagnosing myocardial fibrosis, particularly diffuse myocardial fibrosis in DCM, and T1 mapping parameters are significantly negatively correlated with EF.

[Analysis of BK virus infection in kidney transplant recipients].

Objective: To compare the infection of BK virus in the recipients of living donor(LD) kidney transplant and deceased donor(DD) kidney transplant. Methods: A total of 911 recipients who underwent kidney transplantation in the Organ Transplantation Research Institute of the 8th Medical Center of the People's Liberation Army General Hospital from January 2015 to August 2019 were enrolled in this study. The DNA copies of BK virus in urine and peripheral blood of kidney transplant recipients were detected by real-time quantitative PCR. The patients were divided into LD group (n=255) and DD group (n=656). BK virus infection in recipients with DD kidney transplant were compared with that in recipients of LD kidney transplant. Results: The BK virus positive rate in the urine of all subjects was 13.06%(119/911), and that in blood was 2.96% (27/911). The positive rate of BK virus in urine after kidney transplantation was significantly higher than that in blood(P<0.000 1). The positive rate in urine was 9.02% (23/255) in LD group, which was significantly lower than that of 14.63% (96/656) in DD group in the same period (χ(2)=5.097, P=0.012); The positive rate of BK virus infection in relatives group was 0.78% (2/255), which was significantly lower than that of 3.81% (25/656) in DD group (χ(2)=5.849, P=0.007). Conclusions: There was a significant difference in the infection rate of BK virus between the LD and DD group. The incidence of BK virus infection in kidney transplant recipients from DD was higher than that of from LD kidney transplant recipients.

[Ten cases of wound hemostasis with glove bandaging in hand skin grafting].

From July 2018 to April 2019, 10 patients (8 males and 2 females, aged 5 to 53 years) who need skin grafting with 17 hands were admitted to the Fourth Medical Center of PLA General Hospital. The method of glove bandaging was used for wound hemostasis in skin grafting. After the initial hemostasis, sterile latex gloves were used as the inner cover of hand, and then pressure-wrapped with gauze. After 20 minutes, the gauze and gloves were removed in order from the near to the far, then thorough hemostasis was conducted again, and finally skin grafting was performed. The use of gloves as inner cover can avoid the adhesion of gauze fibers to the wound surface, so that it will not cause small blood vessels to re-bleed when the gauze is removed, therefore reducing the excessive use of electrocoagulation and secondary damage to the wound. As a result, blood loss can be reduced and hemostatic time can be shortened.

Hollow Plasma Acceleration Driven by a Relativistic Reflected Hollow Laser.

In order to address the present difficulty in experimentally generating the relativistic Laguerre-Gaussian laser, primarily due to damage caused to optical modulators, a high-reflectivity phase mirror is applied in the femtosecond petawatt laser system to generate a relativistic hollow laser at the highest intensity of 6.3×10^{19} W/cm^{2} for the first time. A simple optical model is used to verify that the vortex laser may be generated in this new scheme; using such a relativistic vortex laser, the hollow plasma drill and acceleration are achieved experimentally and proven by particle-in-cell simulations. With the development of the petawatt laser, this scheme opens up possibilities for the convenient production of the relativistic hollow laser at high repetition and possible hollow plasma acceleration, which is important for a wide range of applications such as the generation of radiation sources with orbital angular momentum, fast ignition for inertial confinement fusion, and jet research in the astrophysical environment.

[Study on the matching feature of current parameters for inducing contraction of orbicularis oris muscle by artificial facial nerve in rabbit with peripheral facial paralysis].

Objective: To explore the optimal matching of the current parameters about artificial facial nerve (AFN) for inducing contraction of the orbicularis oris muscle (OOM) in rabbit with peripheral facial paralysis. Methods: According to the combinations of different stimulus parameters, at different time points, we used AFN to induce contraction of the affected side OOM of the paralyzed rabbit in waking state. We recorded the current amplitudes of the threshold stimulation and peak stimulation under each combination, then compared the total charge of the stimulus consumption under different combinations. Results: Compared the total stimulus charge consumption of the AFN threshold stimulation and that in the peak stimulation respectively under different stimulus frequency and pulse width matching combinations, we found that the frequency, the pulse width and the interaction of the frequency and pulse width among different groups could affect the total charge, the differences were statistically significant (P<0.05). Conclusions: When AFN stimulus frequency is 60 Hz and the stimulus pulse width is 100 µs, the output current intensity is relatively lowest and the total consumed charge is the lowest under the premise of effectively inducing the paralytic side OOM contraction. Thus we recommend this stimulus parametric combination as the optimal combination for meeting the low power consumption of AFN.