Self-compression of stimulated Raman backscattering by a flying focus

The regime of self-compression has been proposed for plasma-based backward Raman amplification upon a flying focus. By using a pumping focus moving with a speed equal to the group velocity of stimulated Raman backscattering (SRBS), only a short part of SRBS which always synchronizes with the flying focus can be amplified. Therefore, instead of a short pulse, plasma noise or a long pulse can seed the BRA amplifiers. Here we demonstrate the regime by 2D particle-in-cell simulations, showing that the pump pulse is compressed from 26 ps to 116 fs, with an output amplitude comparable with the case of a well-synchronized short seed. As only one laser pulse is used in the simulation, the results present a significant path to simplify the Raman amplifiers.

[The influence of sacroiliac joint reduction quality on the clinical effect of bionic reduction and internal fixation for pelvic ring injury]

Objective: To examine the influence of sacroiliac joint reduction quality on the clinical effect of bionic reduction and internal fixation for pelvic ring injury. Methods: From January 2014 to February 2019,the clinical data of 78 patients diagnosed with pelvic ring injury involving sacroiliac joints and treated with bionic reduction and internal fixation at Honghui Hospital Affiliated to Medical College of Xi'an Jiaotong University were retrospectively analyzed.There were 48 males and 30 females,aged (48.3±8.3)years (range:28 to 68 years).After bionic reduction and internal fixation,the patients were grouped according to the maximum displacement distance (d) of sacroiliac joint residual on the damaged side measured by CT examination. Patients with d≤5 mm were included in anatomical bionic reduction group,and patients with d>5 mm were included in non-anatomical bionic reduction group.In non-anatomical bionic reduction group,according to the direction of residual displacement,the patients were divided into separation displacement group and anterior-posterior displacement group. The X-ray examination was performed immediately and at the last follow-up after operation.If sacroiliac joint was relocated,or internal plant loosening,displacement,fracture and re-displacement of fracture,it was defined as internal fixation failure.Majeed pelvic fracture scoring system was used to evaluate the postoperative functional status of the two groups,and visual analogue scale (VAS) was used to evaluate the postoperative pain.Comparison between groups was performed by completely random design ANOVA,χ² test,Fisher's exact test,Mann-Whitney U and Kruskal-Wallis H test. Results: According to the CT examination,28 cases were included in anatomical bionic reduction group,and 50 cases were included in non-anatomical bionic reduction group.In non-anatomical bionic reduction group,27 cases were divided into separation displacement group and 23 cases were in anterior-posterior displacement group.There was no significant difference in general data among anatomical bionic reduction group,separation displacement group and anterior-posterior displacement group (P>0.05). The follow-up time was (37.8±6.6) months (range:25 to 51 months). At the last follow up,the excellent and good rate of Majeed score in anatomical bionic reduction group was 96.4%(27/28),which was better than that in separation displacement group(74.1%(20/27)) and anterior-posterior displacement group (30.4%(7/23)),the difference was statistically significant (Z=-6.479,P<0.01;Z=-6.256,P<0.01); and the good rate of the separation displacement group was better than that of the anterior-posterior displacement group(Z=-3.607,P<0.01).The VAS of anatomical bionic reduction group (17 cases with 0 point, 11 cases with 1 to 3 points) were lower than that of the displacement group (6 cases with 0 point,16 cases with 1 to 3 points,5 cases with 4 to 6 points) and anterior-posterior displacement group (3 cases with 0 point,7 cases with 1 to 3 points,13 cases with 4 to 6 points),the difference was statistically significant (Z=-3.515,P<0.01;Z=-3.506,P<0.01),and there was no difference between separation displacement group and anterior-posterior displacement group.Total of 8 cases of internal fixation failure occurred,and the failure rate of anatomical bionic reduction group (0,0/28) was lower than that of the separation displacement group (11.1%,3/27) and anterior-posterior displacement group (21.7%,5/23) (P=0.111,P=0.014),and there was no difference between separation displacement group and anterior-posterior displacement group(P=0.444). Conclusions: In the bionic reduction and internal fixation of pelvic fracture involving sacroiliac joint injury,the functional status,pain and internal fixation failure rate of patients with anatomical bionic reduction of sacroiliac joint are significantly better than those in the non-anatomical bionic reduction.The functional recovery of patients with separation displacement is better than that of the patients with anterior and posterior displacement.

Genetic engineering for enhanced production of a novel alkaline protease BSP-1 in Bacillus amyloliquefaciens

Alkaline protease has been widely applied in food, medicine, environmental protection and other industrial fields. However, the current activity and yield of alkaline protease cannot meet the demand. Therefore, it is important to identify new alkaline proteases with high activity. In this study, we cloned a potential alkaline protease gene bsp-1 from a Bacillus subtilis strain isolated in our laboratory. BSP-1 shows the highest sequence similarity to subtilisin NAT (S51909) from B. subtilis natto. Then, we expressed BSP-1 in Bacillus amyloliquefaciens BAX-9 and analyzed the protein expression level under a collection of promoters. The results show that the P43 promoter resulted in the highest transcription level, protein level and enzyme activity. Finally, we obtained a maximum activity of 524.12 U/mL using the P43 promoter after fermentation medium optimization. In conclusion, this study identified an alkaline protease gene bsp-1 from B. subtilis and provided a new method for high-efficiency alkaline protease expression in B. amyloliquefaciens.

[An analysis on senior pupil's tobacco use and exposure in Shandong province in 2012 and 2019]

Objective: To analyze the changes in tobacco use and exposure in primary school students in Shandong province in 2012 and 2019. Methods: A multi-stage stratified cluster random sampling method was used in the survey. In 2012 and 2019, 5 861 and 4 021 students from 3 different cities of Shandong province were selected as the study population. The questionnaire was filled anonymously by the subjects. χ² test was conducted to compare the difference of groups. Results: In 2012 and 2019, the rate of attempting smoking among pupils under this study in Shandong province were 6.0％and 6.3%, respectively, while the current smoking rate were 1.2％and 2.3%, respectively. The sex ratio of male and female students attempting to smoke was 2.56∶1 in 2012 and 1.31∶1 in 2019. The sex ratio of current smoking rate was 2.43∶1 and 2.00∶1, respectively in 2012 and in 2019. The rate of tobacco exposure in the public places was 50.5％and 41.4%, respectively. The rate of tobacco exposure in family was 49.7% and 46.4%, respectively. Two rates of tobacco exposure decreased, but the reduction in family (3.3%) was far less than that in public places (9.1%). In 2019, the rate of tobacco exposure in family was higher than that in public places. Conclusions: The tobacco exposure rate declined in senior pupils in Shandong province. However, the situation is still grim for the current smoking rate, growth trend of girls tobacco use, and tobacco exposure in family.

Regulation of Alfvén Eigenmodes by Microturbulence in Fusion Plasmas

Global gyrokinetic simulations of mesoscale reversed shear Alfven eigenmodes (RSAE) excited by energetic particles (EP) in fusion plasmas find that RSAE amplitude and EP transport are much higher than experimental levels at nonlinear saturation, but quickly diminish to very low levels after the saturation if background microturbulence is artificially suppressed. In contrast, in simulations coupling micro-meso scales, the RSAE amplitude and EP transport decrease drastically at the initial saturation but later increases to the experimental levels in the quasisteady state with bursty dynamics due to regulation by thermal ion temperature gradient (ITG) microturbulence. The quasisteady state EP transport is larger for a stronger microturbulence. The RSAE amplitude in the quasisteady state ITG-RSAE turbulence from gyrokinetic simulations, for the first time, agrees very well with experimental measurements.

A comprehensive review of spermidine: Safety, health effects, absorption and metabolism, food materials evaluation, physical and chemical processing, and bioprocessing

Spermidine, a natural autophagy inducer, has a variety of health effects, such as antitumor, antiaging, anti-inflammation, cardiovascular protection, and neuromodulation. It has been a hot topic in the field of food processing, and current research findings suggest that spermidine-rich foods may be used in intervention and prevention of age-related diseases. In this article, recent findings on the safety, health effects, absorption and metabolism of spermidine were reviewed, and advances in food processing, including the raw materials evaluation, physical and chemical processing, and biological processing of spermidine, were highlighted. In particular, the core metabolic pathways, key gene targets, and efficient metabolic engineering strategies involved in the biosynthesis of spermidine and its precursors were discussed. Moreover, limitations and future perspectives of spermidine research were proposed. The purpose of this review is to provide new insights on spermidine from its safety to its food processing, which will advance the commercial production and applications of spermidine-rich foods and nutraceuticals.

[Ultrasonographic features and clinical pathological of liver metastasis in patients with melanoma]

Objective: To investigate the ultrasonographic features and clinical pathological of liver metastasis in patients with melanoma. Methods: Thirteen patients with liver metastasis from melanoma treated in Tianjin Medical University Cancer Institute and Hospital from 2013 to 2019 were selected, and their ultrasonographic and clinicopathological characteristics were analyzed retrospectively. Results: Eleven of the 13 patients had multiple liver lesions. The maximum diameter of the lesions was (5.89±2.73) cm. Five cases of lesions were mixed echo (3 cases with high melanin content), 4 cases of lesions were hyperechoic (3 cases with low melanin content), 3 cases of lesions were hypoechoic (all with high melanin content), 1 case of lesions were equal echo (with high melanin content). The lesions in 11 patients had clear boundaries, while other 2 patients lacked the clear borders. Cystic areas were present in the lesions of 3 patients. Six cases had irregular lesions (lobulated), and 7 cases had regular lesions (round, oval). There were acoustic halos around the lesion in 9 cases and smooth and uneven acoustic halos in 5 cases. The results of immunohistochemistry showed that 11 cases were positive for S-100, HMB45 and Melan-A. One patient was not tested for HMB45, while S-100 and Melan-A were positive. One patient did not undergo Melan-A test, while S-100 and HMB45 were positive. Conclusion: Most of the liver metastases of melanoma are mixed echo or hyperechoic, most of them are nodular with clear boundaries combined with vocal halo, and a few of the lesions have cystic areas.

[Application status and prospect of single-cone obturation technique with bioceramic sealers]

Compared with cold lateral condensation and continuous wave of condensation which are classically used in clinical, newly emerging single-cone obturation technique is easy-to-operate as well as time-saving. Especially when combined with bioceramic root canal sealers of improved physicochemical and biological properties, single-cone obturation technique showed satisfactory short-term outcomes in clinical observations. However, difficulties still exist in avoiding the root canal overfilling and in operating the retreatment. Besides, the long-term effects of single-cone obturation with bioceramic sealers still remain unclear. This article makes an overview on the history and development of single-cone obturation ,and provides analysis of its pros and corns. Furthermore, we would also like to summarize its clinical application and look into its future improvements.

Development and validation of an individualized nomogram for predicting the high-volume (> 5) central lymph node metastasis in papillary thyroid microcarcinoma

PURPOSE

Papillary thyroid microcarcinoma (PTMC) frequently presents a favorable clinical outcome, while aggressive invasiveness can also be found in some of this population. Identifying the risk clinical factors of high-volume (> 5) central lymph node metastasis (CLNM) in PTMC patients could help oncologists make a better-individualized clinical decision.

METHODS

We retrospectively reviewed the clinical characteristics of adult patients with PTC in the Surveillance, Epidemiology, and End Results (SEER) database between Jan 2010 and Dec 2015 and in one medical center affiliated to Chongqing Medical University between Jan 2018 and Oct 2020. Univariate and multivariate logistic regression analyses were used to determine the risk factors for high volume of CLNM in PTMC patients.

RESULTS

The male gender (OR = 2.02, 95% CI 1.46-2.81), larger tumor size (> 5 mm, OR = 1.64, 95% CI 1.13-2.38), multifocality (OR = 1.87, 95% CI 1.40-2.51), and extrathyroidal invasion (OR = 3.67; 95% CI 2.64-5.10) were independent risk factors in promoting high-volume of CLNM in PTMC patients. By contrast, elderly age (≥ 55 years) at diagnosis (OR = 0.57, 95% CI 0.40-0.81) and PTMC-follicular variate (OR = 0.60, 95% CI 0.42-0.87) were determined as the protective factors. Based on these indicators, a nomogram was further constructed with a good concordance index (C-index) of 0.702, supported by an external validating cohort with a promising C-index of 0.811.

CONCLUSION

A nomogram was successfully established and validated with six clinical indicators. This model could help surgeons to make a better-individualized clinical decision on the management of PTMC patients, especially in terms of whether prophylactic central lymph node dissection and postoperative radiotherapy should be warranted.

The function of the ACE2/Ang(1-7)/Mas receptor axis of the renin-angiotensin system in myocardial ischemia reperfusion injury

OBJECTIVE

Angiotensin-converting enzyme 2(ACE2) is a critical element of the renin-angiotensin system (RAS), which can convert angiotensin (Ang)II to Ang(1-7), followed by binding Mas receptor (MasR) and subsequently produces cardioprotective effects through various signal transduction pathways. It has been discovered in research that activation of the RAS contributes a crucial influence during the myocardial ischemia reperfusion injury (MIRI) development. The features of ACE2, Ang(1-7), and MasR, as well as the function of the ACE2/Ang(1-7)/MasR axis in MIRI, are discussed in our review, with the therapeutic potential of this axis as a new treatment option for MIRI patients shown.

MATERIALS AND METHODS

To retrieve a thorough collection of studies, we performed a search in PubMed using the following combination of keywords: (ACE2) or (Ang1-7) or (Mas receptor) and (Myocardial Ischemia reperfusion injury). The time limits used for the search were 1986 to 2021.

RESULTS

In total, 367 articles were included. Titles and abstracts of articles were screened for relevance, and all relevant articles published in English were included.

CONCLUSIONS

ACE2, a prominent member of the RAS, performs a crucial regulatory function in the cardiovascular system. ACE2 regulates the RAS inversely mainly by hydrolyzing the harmful AngII to the beneficial Ang(1-7). Increasing or activating ACE2 or Ang(1-7) may help prevent and treat MIRI. However, additional research into the specific processes behind the ACE2/Ang(1-7)/MasR axis in MIRI is necessary, as well as the performance of additional in-depth studies to go from basic research to clinical translation.

[Preliminary clinical experience of the novel transcatheter aortic valve system Prizvalve® for the treatment of severe aortic stenosis]

Objective: To evaluate the safety and efficacy of transcatheter aortic valve implantation (TAVI) with the novel Prizvalve^® system in treating severe aortic stenosis. Methods: This is a single-center, prospective, single-arm, observational study. A total of 11 patients with severe aortic stenosis with high risk or inappropriate for conventional surgical aortic valve replacement (SAVR) were included, and TAVI was achieved with the Prizvalve^® system between March 2021 and May 2021 in West China Hospital. Transthoracic echocardiography (TTE) was performed immediately after prosthesis implantation to evaluate mean transaortic gradient and maximal transaortic velocity. The device success rate was calculated, which was defined as (1) the device being delivered via the access, deployed, implanted and withdrawn, (2) mean transaortic gradient<20 mmHg (1 mmHg=0.133 kPa) or a maximal transaortic velocity<3 m/s post TAVI, and without severe aortic regurgitation or paravalvular leak post TAVI. TTE was performed at 30 days after the surgery, and all-cause mortality as well as the major cardiovascular adverse events (including acute myocardial infarction, disabling hemorrhagic or ischemic stroke) up to 30 days post TAVI were analyzed. Results: The age of 11 included patients were (78.1±6.3) years, with 8 males. A total of 10 patients were with NYHA functional class Ⅲ or Ⅳ. Devices were delivered via the access, deployed, implanted and withdrawn successfully in all patients. Post-implant mean transaortic gradient was (7.55±4.08) mmHg and maximal transaortic velocity was (1.78±0.44) m/s, and both decreased significantly as compared to baseline levels (both P<0.05). No severe aortic regurgitation or paravalvular leak was observed post TAVI. Device success was achieved in all the 11 patients. No patient died or experienced major cardiovascular adverse events up to 30 days post TAVI. Mean transaortic gradient was (9.45±5.07) mmHg and maximal transaortic velocity was (2.05±0.42) m/s at 30 days post TAVI, which were similar as the values measured immediately post TAVI (both P>0.05). Conclusions: TAVI with the Prizvalve^® system is a feasible and relatively safe procedure for patients with severe aortic stenosis and at high risk or inappropriate for SAVR. Further clinical studies could be launched to obtain more clinical experience with Prizvalve^® system.

Multidimensional, High Precision Measurements of Beam Single Spin Asymmetries in Semi-inclusive π^{+} Electroproduction off Protons in the Valence Region

High precision measurements of the polarized electron beam-spin asymmetry in semi-inclusive deep inelastic scattering (SIDIS) from the proton have been performed using a 10.6 GeV incident electron beam and the CLAS12 spectrometer at Jefferson Lab. We report here a high precision multidimensional study of single π^{+} SIDIS data over a large kinematic range in Bjorken x, fractional energy, and transverse momentum of the hadron as well as photon virtualities Q^{2} ranging from 1-7  GeV^{2}. In particular, the structure function ratio F_{LU}^{sinϕ}/F_{UU} has been determined, where F_{LU}^{sinϕ} is a twist-3 quantity that can reveal novel aspects of emergent hadron mass and quark-gluon correlations within the nucleon. The data's impact on the evolving understanding of the underlying reaction mechanisms and their kinematic variation is explored using theoretical models for the different contributing transverse momentum dependent parton distribution functions.

Systematic Metabolic Engineering for the Production of Azaphilones in Monascus purpureus HJ11

Fungal azaphilones have attracted considerable interest as they exhibit great potential in food and pharmacological industries. However, there is a severe bottleneck in the low production in wild strains and the ability to genetically engineer azaphilone-producing fungi. Using Monascus azaphilones (MAs) as an example, we demonstrate a systematic metabolic engineering strategy for improving the production of MAs. In this study, Monascus purpureus HJ11 was systematically engineered through a combination of promoter engineering, gene knockout, rate-limiting enzyme overexpression, repression of the competing pathway, enzyme engineering, and metabolic rebalance. The maximum yield and titer of MAs successfully increased to 906 mg/g dry cell weight (DCW) and 14.6 g/L, respectively, 2.6 and 3.7 times higher than those reported in the literature. Our successful model not only offers a practical and efficient way to improve the azaphilone production but also sheds light on the potential of systematic metabolic engineering in nonmodel fungi as a chassis for the production of high-value chemicals.

Preoperative MRI of breast squamous cell carcinoma: diagnostic value of distinguishing between two subtypes

AIM

To retrospectively analyse the clinical and MRI data of primary squamous cell carcinoma (SCC), particularly pure squamous cell carcinoma (PSCC) and mixed squamous cell carcinoma (MSCC).

MATERIALS AND METHODS

The MRI data and clinicopathological characteristics of 20 patients with histopathologically confirmed SCC of the breast, including eight PSCC patients and 12 MSCC patients, from multiple centres between January 2013 and December 2020 were analysed retrospectively.

RESULTS

Nine of 12 patients in the MSCC group showed hyperintensity on T1-weighted imaging (WI), while this feature was not observed in the PSCC group (p=0.001). Most of the PSCC group showed rim enhancement, whereas most of the MSCC group showed heterogeneous enhancement (p=0.007). In addition, there was no significant difference in the thickness of the rim enhancement and the percentage of necrotic components in the tumours between the two types of SCCs of the breast (p=0.545 and p=0.662, respectively). Four patients (4/12) in the MSCC group had sentinel lymph node metastasis, while only one patient (1/8) in the PSCC group showed lymph node metastasis (p=0.603). Metastatic disease occurred in 25% of patients with PSCC and in approximately 41.7% of patients with MSCC.

CONCLUSION

The signal on T1WI and internal enhancement characteristics were the key features for differentiating PSCC and MSCC. Therefore, MRI phenotypes may provide additional information for the pathological classification of breast SCC.

[Application and prospect of static/dynamic guided endodontics for managing pulpal and periapical diseases]

Root canal therapy and endodontic surgery are conventional treatments for pulpal and periapical diseases. Compared with naked-eye operations, the application of dental operating microscope has enhanced the procedural accuracy and prognosis efficiently. However, root canals with pulp calcification/obliteration, apical lesions with thick cortical bone or adjacent to important anatomic structures are even challenging for experienced operators to achieve predictable clinical outcomes. Recently, with the advances in the field of digitalized information sciences, the above mentioned complicated endodontic cases can be solved under static and dynamic guidance. Before the treatment begins, virtual path is designed from data collected by cone-beam CT and oral image scanning using guidance software. Afterwards, root canal therapy and endodontic surgery can be performed precisely under the assistance of three-dimensional printed guide or dynamic guidance system. The present review describes the classification, features and clinical applications of the guided endodontics.