Generation of attosecond electron bunches of tunable duration and density by relativistic vortex lasers in near-critical density plasma.

Attosecond electron bunches have wide application prospects in free-electron laser injection, attosecond X/γ-ray generation, ultrafast physics, etc. Nowadays, there is one notable challenge in the generation of high-quality attosecond electron bunch, i.e., how to enhance the electron bunch density. Using theoretical analysis and three-dimensional particle-in-cell simulations, we discovered that a relativistic vortex laser pulse interacting with near-critical density plasma can not only effectively concentrate the attosecond electron bunches to over critical density, but also control the duration and density of the electron bunches by tuning the intensity and carrier-envelope phase of the drive laser. It is demonstrated that this method can efficiently produce attosecond electron bunches with a density up to 300 times of the original plasma density, peak divergence angle of less than 0.5 ∘, and duration of less than 67 attoseconds. Furthermore, by using near-critical density plasma instead of solid targets, our scheme is potential for the generation of high-repetition-frequency attosecond electron bunches, thus reducing the requirements for experiments, such as the beam alignment or target supporter.

[Clinical study of serum human-ßeta-defensin-1 level for evaluating short-term prognosis in patients with acute-on-chronic liver failure].

Objective: To evaluate the diagnostic value of serum human-ßeta-defensin-1 level (HBD-1) for short-term (28-day) prognosis in patients with acute-on-chronic liver failure (ACLF). Methods: Fifty cases diagnosed with ACLF were selected. 20 cases with decompensated cirrhosis and 20 cases with compensated cirrhosis who were admitted at the same time were included. Age, gender, serum HBD-1 level, C-reactive protein (CRP), procalcitonin (PCT), neutrophil count/lymphocyte ratio (NLR), blood routine, coagulation function, liver function, kidney function, and other indicators from the three groups of patients were collected. Patients with ACLF were screened for indicators related to the short-term (28-day) prognosis. Patients were divided into an improvement group and a worsening group according to the 28-day disease outcome. The serum HBD-1 level and other above-mentioned indicators were compared between the two patient groups. The receiver operating characteristic (ROC) curve was used to analyze the diagnostic efficacy of serum HBD-1 levels for short-term prognosis in patients with ACLF. PCT, NLR, and prothrombin activity (PTA) application as a mono indicator and HBD-1 in combination with NLR, PCT, and PTA were compared to evaluate diagnostic efficacy for short-term prognosis in patients with ACLF. The intergroup mean of measurement data was determined using a t-test or analysis of variance. χ (2) test was used for comparison of count data. Spearman's rank correlation analysis was used for correlation analysis. Results: There was no statistically significant difference in age and gender among the three groups: ACLF, decompensated cirrhosis, and compensated cirrhosis (P > 0.05). The expression levels of serum HBD-1 in the ACLF group, decompensated cirrhosis group, and compensated cirrhosis group were (319.1 ± 44.4) ng/ml, (264.5 ± 46.5) ng/ml and (240.1 ± 35.4) ng/ml, respectively, while the ACLF group expression levels were significantly increased, with statistical significance (P < 0.01).The serum HBD-1 level was significantly higher in the ACLF worsening group (346.2 ± 43.6) ng/ml than that in the improvement group (308.5 ± 40.6) ng/ml, and the difference was statistically significant (P < 0.05). Correlation analysis showed that HBD-1, NLR, PCT, prothrombin time (PT), and international standardized ratio (INR) were negatively correlated with the 28-day disease outcome (improvement) of patients (P < 0.05). PTA was positively correlated with 28-day disease outcome (improvement) (P < 0.05). The area under the receiver operating characteristic curve (AUC) for evaluating HBD-1's diagnostic efficacy for short-term prognosis in patients with ACLF was 0.774, with a sensitivity of 0.750, a specificity of 0.786, and a cut-off point of 337.96 ng/ml. PCT, NLR, and PTA had greater diagnostic efficacy. HBD-1 combined with PTA had the highest diagnostic efficacy, with an AUC of 0.802, a sensitivity of 0.778, and a specificity of 0.786. The diagnostic efficacy of HBD-1+PCT, HBD-1+NLR and HBD-1, PCT, and NCR was superior to PTA mono. Conclusion: The serum HBD-1 level gradually increases with the aggravation of liver function injury and is negatively correlated with the short-term prognosis in patients with ACLF. Serum HBD-1 level has high sensitivity and specificity in predicting short-term prognosis in patients with ACLF, and its diagnostic efficacy is superior to that of PCT, NLR, and PTA. The combined application of HBD-1 and PTA has higher diagnostic efficacy; however, when the serum HBD-1 level is greater than 337.96ng/ml, it indicates poor prognosis in patients.

[A study on the diagnostic value of GP73 in liver fibrosis among patients with chronic liver disease].

Objective: This study aimed to evaluate the diagnostic value of serum Golgi protein 73(GP73) alone and GP73 combined with liver stiffness measurement (LSM), aspartate aminotransferase/platelet ratio index (APRI), and 4-factor-based fibrosis index (FIB4) in diagnosing liver fibrosis in patients with chronic liver disease of different etiologies. Methods: A diagnostic test. A total of 68 patients who underwent liver biopsy in the Department of Traditional and Western Medical Hepatology of the Third Hospital of Hebei Medical University from October 2019 to December 2020 were selected to detect serum GP73 levels. iLivTouch was used to assess liver stiffness measurement (LSM). In addition, serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT), total bilirubin (TBil), direct bilirubin (DBil), triglyceride (TG), total cholesterol (TC), low-density lipoprotein (LDL) levels, and peripheral platelet (PLT) counts were assayed. The correlation between GP73 and the above indexes was assessed, and APRI and FIB-4 were calculated. SPSS 21.0 statistical software was used for statistical analysis. The area under the receiver operating characteristic curve was calculated to evaluate diagnostic efficacy of GP73 in identifying hepatic fibrosis stages. Furthermore, the difference between GP73 and liver stiffness, as well as APRI and FIB4 in diagnosing significant fibrosis was assessed. Results: Based on liver biopsy, 13, 18, 17, and 20 cases were diagnosed as stages S0-1, S2, S3, and S4, respectively. The AUC of GP73 diagnosing hepatic fibrosis stage S≥3 and S=4 were 0.806 and 0.844 at cut-off points of 2.06 and 3.27 µg/L, and the sensitivity and specificity were 93.5%, 61.5%, 90.0%, 70.3%, respectively. In addition, GP73 levels were positively correlated with the degree of liver fibrosis (r=0.547, P<0.001). Conclusions: The efficacy of serum GP73 level in diagnosing the degree of liver fibrosis in patients with chronic liver disease from different causes was significantly higher than that of APRI, FIB4, and LSM. The combination of GP73 and FIB4 can further improve the accuracy of diagnosis of liver fibrosis staging S≥3 and S=4, which is a reliable serological marker for the diagnosis of fibrosis in patients with chronic liver disease.

[Differential diagnosis and management of hemangioma at geniculate ganglion].

Objective: To investigate the clinical characteristics, differential diagnosis, treatments and prognosis of facial nerve hemangioma and schwannoma at genicular ganglion, so as to provide reference for clinical diagnosis and treatments of facial nerve tumor at genicular ganglion. Methods: Clinical data of 13 patients with facial nerve tumors at genicular ganglion confirmed by postoperative pathology in the Ninth People's Hospital affiliated to Shanghai Jiaotong University School of Medicine from March 2018 to April 2020 were retrospectively analyzed, including seven cases of hemangioma and six cases of schwannoma. There were eight males and five females. Their ages ranged from 20 to 65, with an average age of 40. The course of disease ranged from 3 to 118 months, with an average of 52 months. All the patients underwent preoperative HRCT of the temporal bone and facial nerve dynamic contrast-enhanced(DCE) MRI examinations. All the patients had detailed surgical procedures and at least one-year postoperative follow-up. Results: On HRCT of the temporal bone, (4/7) hemangioma at geniculate ganglion showed characteristic honeycomb appearance, while 6/6 schwannoma and 3/7 hemangiomas showed expansive bone changes. On DCE-MRI, geniculate ganglion hemangioma (7/7) showed characteristic "point-to-surface" enhancement, and schwannoma (6/6) showed characteristic "face-to-surface" enhancement. For five hemangioma-patients with HB-Ⅱ-Ⅳ before surgery, the facial nerve anatomy was completely preserved through transcanal endoscopic approach(TEA), and the facial nerve function improved one year after surgery (two cases of HB-I, two cases of HB-Ⅱ, and one case of HB-Ⅲ). For two patients, with preoperative facial nerve function HB-Ⅴ-Ⅵ, since their tumors was inseparable from the nerves, they were performed with facial nerve anastomosis during the surgery, and the facial nerve function was improved to HB-Ⅳ level one year after surgery. For six patients with meningioma whose facial nerve function was greater than or equal to HB-Ⅲ, based on the preoperative hearing level, the involved segments, and duration of facial paralysis, three of them were conducted surgeries through middle cranial fossa approach, one by translabyrinthine approach, and one via mastoid approach. Two patients among them with complete facial paralysis over three years preoperatively were not performed facial nerve anastomosis after total resections of the tumors, and there was no improvement in facial nerve function one year after surgery. Three patients underwent facial nerve anastomosis after total tumor resections, and their facial nerve function was HB-Ⅲ in one patient, HB-Ⅳ in two patients one year after surgery. One patient (preoperative HB-Ⅲ) had a normal hearing level preoperatively, and the tumor involved the labyrinth segment. To protect the hearing, partial tumor was resected through the middle cranial fossa approach, and facial nerve function improved to HB-Ⅱ one year after surgery. Conclusions: Temporal bone HRCT combined with DCE-MRI are useful for the differential diagnosis of hemangioma and schwannoma at geniculate ganglion and provide references for preoperative clinical decision makings. It is extremely necessary to select the appropriate surgical approach based on the patient's hearing and involved segments. For geniculate ganglion hemangioma, early surgery can improve the possibilities of anatomical integrity of facial nerve, thereby improving facial nerve function postoperatively.TEA is a kind of surgical method worth consideration, with the characteristics of minimally invasive, favorable postoperative features, and so on. For schwannoma, one-stage functional reconstruction of the facial nerve is recommended during the resection of the tumors because of the inevitable damage to the anatomical integrity of the facial nerve.

[A study on treatment timing selection and short-term efficacy prediction with changes in cytokine levels before and after non-biological artificial liver treatment in acute-on-chronic liver failure].

Objective: To investigate the efficacy and diagnostic accuracy of changes in cytokine levels before and after non-biological artificial liver (referred to as ABL) treatment in patients with acute-on-chronic liver failure (ACLF) in order to establish a basis for treatment timing selection and short-term (28d) prognosis. Methods: 90 cases diagnosed with ACLF were selected and divided into a group receiving artificial liver treatment (45 cases) and a group not receiving artificial liver treatment (45 cases). Age, gender, first routine blood test after admission, liver and kidney function, and procalcitonin (PCT) of the two groups were collected. The 28-day survival of the two groups was followed-up for survival analysis. The 45 cases who received artificial liver therapy were further divided into an improvement group and a deterioration group according to the clinical manifestations before discharge and the last laboratory examination results as the efficacy evaluation indicators. Routine blood test, coagulation function, liver and kidney function, PCT, alpha fetoprotein (AFP), ß-defensin-1 (HBD-1), 12 cytokines and other indicators were analyzed and compared. A receiver operating characteristic curve (ROC curve) was used to analyze the diagnostic efficacy of the short-term (28 d) prognosis and an independent risk factors affecting the prognosis of ACLF patients. According to different data, Kaplan-Meier method, log-rant test, t-test, Mann-Whitney U test, Wilcoxon rank-sum test, χ2 test, Spearman rank correlation analysis and logistic regression analysis were used for statistical analysis. Results: The 28-day survival rate was significantly higher in ACLF patients who received artificial liver therapy than that of those who did not receive artificial liver therapy (82.2% vs. 61.0%, P<0.05). The levels of serum HBD-1, alpha interferon (IFN-α) and interleukin-5 (IL-5) after artificial liver treatment were significantly lower in ACLF patients than those before treatment (P<0.05), while liver and coagulation function were significantly improved compared with those before treatment (P<0.05), and there was no statistically significant difference in other serological indexes before and after treatment (P＞0.05). Before artificial liver treatment, serum HBD-1 and INF-α levels were significantly lower in the ACLF improvement group than in the deterioration group (P<0.05) and were positively correlated with the patients' prognosis (deteriorating) (r=0.591, 0.427, P<0.001, 0.008). The level of AFP was significantly higher in the improved ACLF group than that in the deterioration group (P<0.05), and was negatively correlated with the prognosis (deteriorating) of the patients (r=-0.557, P<0.001). Univariate logistic regression analysis showed that HBD-1, IFN-α and AFP were independent risk factors for the prognosis of ACLF patients (P=0.001, 0.043, and 0.036, respectively), and that higher HBD-1 and IFN-α levels were associated with lower AFP level and a deteriorating prognosis. The area under the curve (AUC) of HBD-1, IFN-α, and AFP for short-term (28d) prognostic and diagnostic efficacy of ACLF patients was 0.883, 0.763, and 0.843, respectively, and the sensitivity and specificty was 0.75, 0.75, and 0.72, and 0.84, 0.80, and 0.83, respectively. The combination of HBD-1 and AFP had further improved the diagnostic efficiency of short-term prognosis of ACLF patients (AUC=0.960, sensitivity and specificity: 0.909 and 0.880 respectively). The combination of HBD-1+IFN-α+AFP had the highest diagnostic performance, with an AUC of 0.989, sensitivity of 0.900, and specificity of 0.947. Conclusion: Artificial liver therapy can effectively improve the clinical symptoms and liver and coagulation function of patients with ACLF; remove cytokines such as HBD-1, IFN-α, and IL-5 in patients with liver failure; delay or reverse the progression of the disease; and improve the survival rate of patients. HBD-1, IFN-α, and AFP are independent risk factors affecting the prognosis of ACLF patients, which can be used as biological indicators for evaluating the short-term prognosis of ACLF patients. The higher the level of HBD-1 and/or IFN-α, the higher the risk of disease deterioration. Therefore, artificial liver therapy should be started as soon as possible after the exclusion of infection. In diagnosing the prognosis of ACLF, HBD-1 has higher sensitivity and specificity than IFN-α and AFP, and its diagnostic efficiency is greatest when combined with IFN-α and AFP.

Direct acceleration of collimated monoenergetic sub-femtosecond electron bunches driven by a radially polarized laser pulse.

High-quality ultrashort electron beams have diverse applications in a variety of areas, such as 4D electron diffraction and microscopy, relativistic electron mirrors and ultrashort radiation sources. Direct laser acceleration (DLA) mechanism can produce electron beams with a large amount of charge (several to hundreds of nC), but the generated electron beams usually have large divergence and wide energy spread. Here, we propose a novel DLA scheme to generate high-quality ultrashort electron beams by irradiating a radially polarized laser pulse on a nanofiber. Since electrons are continuously squeezed transversely by the inward radial electric field force, the divergence angle gradually decreases as electrons transport stably with the laser pulse. The well-collimated electron bunches are effectively accelerated by the circularly-symmetric longitudinal electric field and the relative energy spread also gradually decreases. It is demonstrated by three-dimensional (3D) simulations that collimated monoenergetic electron bunches with 0.75° center divergence angle and 14% energy spread can be generated. An analytical model of electron acceleration is presented which interprets well by the 3D simulation results.

[Clinical characteristics and survival analysis of eight cases HIV-negative plasmablastic lymphoma].

Objective: To deepen the knowledge of HIV-negative plasmablastic lymphoma (PBL) . Methods: Medical records from 8 HIV-negative PBL patients diagnosed in Peking Union Medical College Hospital from January 1997 to May 2015 were collected, and the clinical features and prognosis of these patients were analyzed. Results: All of these 8 patients were diagnosed as HIV-negative PBL, 3 of 8 patients were males, and others were female. The median age was 60 (43-80) year. Among these patients, 4 cases had underlying immunosuppressive state. These patients all had extra-nodular involvement, and 6 cases of them were at stage Ⅳ according to Ann Arbor Staging, 5 patients had bone marrow involvement. CD38 and CD138 were diffusely positive for all patients, while the positive rate of B cell marker including PAX-5 and Bcl-6 were relative low. 5 of 8 patients had been detected for EBV-DNA, and all of them were negative. The median follow-up for the 7 patients receiving chemotherapy and regular follow-ups was 36 (11-57) months, the median progression-free survival (PFS) was 15 (6-52) months, and the median overall survival was 36 (2-52) months. Among these patients, 4 cases had received chemotherapy combined with Bortezomib, showing 3 cases of effective, but it seems to be difficult to keep the long term efficacy, and disease progression occurred in 2, 9, and 21 months after treatment. 2 patients at stageⅠ-Ⅱ were treated effectively, without disease progression and survival, 5 patients at stage Ⅳacquired the efficacy unsustainably, with a median PFS of 10 (2-21) months and a median overall survival of 12 (6-52) months. Conclusion: HIV-negative PBL is relatively prevalent in elderly patients, and presenting with high invasiveness in clinical, extremely prone to extra-nodular involvement, especially the bone marrow. The immunophenotype of PBL is more resemble to that of plasmacytoma. Patients who were in late stage at diagnosis show poor prognosis.

[Field epidemiological investigation on a foodborne outbreak caused by Staphylococcus aureus enterotoxin, in Hangzhou, 2014].

Objective: To identify the cause on a foodborne breakout in a university of Hangzhou in 2014. Methods: Data on cases were gathered from the out-patient logs of the university affiliated or neighboring hospitals to describe the disease distribution and epidemiological curves. Case-control and field studies on hazard factors were conducted simultaneously. Results: The incubation period was 1.5-5.0 hours, of which the median was 3 during the outbreak. All the cases consumed food from a restaurant called Chen's Snacks nearby their university and suffered from the Staphylococcus aureus enterotoxin. Results from the Staphylococcus enterotoxin testing were positive in 3 stool and 6 food samples, out of the total 18 samples. Conclusion: This foodborne outbreak was caused through food poisoning by vermicelli which was contaminated with Staphylococcus aureus.

Transient scrotal hyperthermia affects human sperm DNA integrity, sperm apoptosis, and sperm protein expression.

This prospective randomized clinical study is aimed to evidence the reproductive impairment of frequent scrotal heat exposure. A total of 20 normozoospermic subjects were randomly divided into two groups to undergo testicular warming in a 43 °C water bath 10 times, for 30 min each time; the subjects in group 1 underwent testicular warming for 10 consecutive days and those in group 2 once every 3 days. Sperm chromatin structure assay (SCSA), sperm mitochondrial membrane potential (MMP), apoptosis, and seminal plasma-soluble Fas (sFas) were analyzed before treatment and every 2 weeks after, for a total of 10 times. In group 1, some critical proteins involved in heat stress, hypoxia, structure, and function of sperm mitochondria and flagella were evaluated before hyperthermia and 2, 6, 10, and 16 weeks after hyperthermia. Both groups showed a reversible increase in the proportion of spermatozoa with a disrupted MMP (both p < 0.05 when the minimums were compared with baseline levels, the same below), sperm apoptosis (both p < 0.01) and high DNA stainability (both p < 0.05). The sFas concentration in both groups showed no obvious changes except one: the value at week 2 was significantly increased over baseline in group 1 (p = 0.036). The level of Bcl-2 decreased significantly at weeks 6 and 10 (p = 0.017 and 0.05, respectively) and recovered to baseline at week 16. Proteins involved in heat stress and mitochondria functions were up-regulated, whereas in flagella structure and function was down-regulated (all p < 0.05). This study demonstrated that transient and frequent scrotal hyperthermia severely and reversibly damaged spermatogenesis, consecutive heat exposure had more serious effects than intermittent exposure, whereas intermittent exposure led to a later recovery of sperm damage.

Sensitive and rapid detection of Pectobacterium atrosepticum by targeting the gyrB gene using a real-time loop-mediated isothermal amplification assay.

UNLABELLED: This study reports the development of a real-time, loop-mediated isothermal amplification (RealAmp) assay for the detection of Pectobacterium atrosepticum (P. atrosepticum). A phylogenetic tree was constructed based on the gyrB gene of P. atrosepticum and related species. Pectobacterium atrosepticum from different sources can be clustered in the same branch with 100% support rate. The RealAmp primers targeting the gyrB gene of P. atrosepticum worked most efficiently at 61·0°C. Compared with 55 related bacterial strains, the eight P. atrosepticum strains displayed positive reaction in the RealAmp assay. The melting temperature (Tm) of P. atrosepticum amplified products was about 85·0°C. The detection limit of the RealAmp assay for the detection of P. atrosepticum in pure culture was approx. 3 CFU reaction(-1) . The detection limit of the RealAmp assay for the detection of P. atrosepticum in artificially contaminated samples was 22 CFU reaction(-1) . The detection rate of the RealAmp assay for the detection of potato tubers was 28·5-32·0% higher than that of the conventional PCR. In summary, a specific, sensitive and rapid RealAmp assay based on the gyrB gene of P. atrosepticum, which can be easily performed and real-time monitored, was established. SIGNIFICANCE AND IMPACT OF THE STUDY: Potato blackleg caused by Pectobacterium atrosepticum (P. atrosepticum) which is mainly transmitted through the seed potato leads to the decline in potato production. To reduce yield loss, rapid detection of P. atrosepticum in seed potato remains essential. Based on the gyrB gene of P. atrosepticum, species-specific primers were designed. A real-time, loop-mediated isothermal amplification (RealAmp) assay was established for the detection of P. atrosepticum. The RealAmp assay is a specific, rapid and sensitive method for P. atrosepticum detection. Therefore, it provides an effective diagnosis of potato blackleg in both the growing and stored potato.

[Relationship and influencing factors between the amplitude change of supramaximal facial nerve stimulation during acoustic neuroma removal and facial function outcome].

OBJECTIVE: To investigate the relationship between the amplitude change of supramaximal facial nerve stimulation during acoustic neuroma removal and facial function outcome, and discuss its influencing factors. METHODS: Retrospective study of 34 acoustic neuroma patients. Intraoperative amplitude by supramaximal stimulation, facial function outcome, tumor size, surgical approach, facial nerve course pattern, and tumor cystic status, as well as tumor adhesion degree were collected and analyzed by SPSS 17.0. RESULTS: Acoustic neurnomas were removed in all 34 patients without intra- and postoperative complications, the facial nerve were all anatomically preserved. Two weeks later, 5 cases showed facial function HB Grade Ⅰ, 13 HB Ⅱ, 11 HB Ⅲ and 5 HB Ⅳ. The amplitude changes under supramaximal stimulation after tumor removal were 12.9%-100%, average (63.9±25.7)%. The facial function outcomes were poor (HB Ⅳ) in the cases whose intraoperative amplitude decreases were more than 70%. Different postoperative facial function group showed significantly different intraoperative amplitude changes (F=7.585, P=0.001), except HB Ⅰ group and HB Ⅱ group. The existence of cystic degeneration showed strong correlation (r=-0.635) to the amplitude changes, the level of tumor adhesion showed moderately negative correlation (r=-0.455), and tumor size showed weak negative correlation (r=-0.292), surgical approach and the facial nerve course pattern were not statistically relevant. CONCLUSIONS: The amplitude change of facial nerve supramaxial stimulation can predict the postoperative facial function. The amplitude change is valuable for early treatment of facial nerve damage.

Reaction kinetics for the solid state synthesis of the AlH3/MgCl2 nano-composite by mechanical milling.

The process of mechanical milling has been proved to be a cost-effective way to synthesize the AlH3/MgCl2 nano-composite by using MgH2 and AlCl3 as reagents. However, so far there is no comprehensive knowledge of the kinetics of this process. In an effort to predict the reaction progress and optimize the milling parameters, the kinetics of the synthesis of the AlH3/MgCl2 nano-composite by mechanical milling of MgH2 and AlCl3 is experimentally investigated in the present work. The reaction progress or the transformation fraction upon milling for different times is evaluated using the isothermal hydrogen desorption test of the as-milled samples at 220 °C, which is much lower than the threshold temperature for the de-hydriding of the reagent MgH2 but enough for the de-hydriding of the as-synthesized nano-sized AlH3. The effects of milling parameters on the reaction kinetics as well as the underlying mechanism are discussed by referring to the mechanical energy input intensity, the vial temperature and the Gibbs free energy change for the reaction. Furthermore, it is found that the Johnson-Mehl-Avrami (JMA) model can well describe the kinetics theoretically. By fitting the experimental data with the JMA expression, the theoretical kinetics expressions, the equation parameters, and the activation energy are obtained.