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Introduction. Radiomics could be potential imaging biomarkers by capturing and analyzing the features. Children and adolescents with CHD have worse neurodevelopmental and functional outcomes compared with their peers. Early diagnosis and intervention are the necessity to improve neurological outcomes in CHD patients. Methods. School-aged TOF patients and their healthy peers were recruited for MRI and neurodevelopmental assessment. LASSO regression was used for dimension reduction. ROC curve graph showed the performance of the model. Results. Six related features were finally selected for modeling. The final model AUC was 0.750. The radiomics features can be potential significant predictors for neurodevelopmental diagnoses. Conclusion. The radiomics on the conventional MRI can help predict the neurodevelopment of school-aged children and provide parents with rehabilitation advice as early as possible.

The relationship between smoking and coronavirus disease 2019 (COVID-19) severity remains unclear. This study aimed to investigate the effect of smoking status (current smoking and a smoking history) on the clinical severity of COVID-19. Data of all enrolled 588 patients, who were referred to 25 hospitals in Jiangsu province between January 10, 2020 and March 14, 2020, were retrospectively reviewed. Univariate and multivariate regression, random forest algorithms, and additive interaction were used to estimate the importance of selective predictor variables in the relationship between smoking and COVID-19 severity. In the univariate analysis, the proportion of patients with a current smoking status in the severe group was significantly higher than that in the non-severe group. In the multivariate analysis, current smoking remained a risk factor for severe COVID-19. Data from the interaction analysis showed a strong interaction between the number of comorbidities in patients with COVID-19 and smoking. However, no significant interaction was found between smoking and specific comorbidities, such as hypertension, diabetes, etc. In the random forest model, smoking history was ranked sixth in mean decrease accuracy. Active smoking may be significantly associated with an enhanced risk of COVID-19 progression towards severe disease. However, additional prospective studies are needed to clarify the complex relationship between smoking and COVID-19 severity.

Chronic musculoskeletal pain (CMP) management is a major global public health goal owing to increased social and economic burdens. However, the risk of CMP in smokers compared with nonsmokers remains uncertain.This study aims to determine the magnitude and importance of the relationship between cigarette smoking and risk of CMP.A meta-analysis of the CMP risk of cigarette smokers.We systematically searched PubMed, Embase, and Cochrane library databases from inception to August 2020. Data extraction and quality assessment were performed by 2 independent reviewers using a standardized extraction checklist. Data were pooled using a random-effects model.In this meta-analysis of 32 studies involving 296,109 participants, current smoking was associated with increased CMP risk (OR: 1.23, 95% CI: 1.09-1.40), whereas ever and past smoking did not show such an association (OR: 1.14, 95% CI: 0.95-1.37; OR: 1.06, 95% CI: 0.83-1.35, respectively). Stratified analyses showed that there was a marked significance in almost all strata of current smokers compared with non-smokers, except for mean age (= 50 years), location of pain (neck pain, sacral pain, and knee pain), smoking frequency (occasionally), study design (cross-sectional), mean follow-up (10 years), and adjustment for confounding factors (= 6). Interestingly, there was statistically negative association between cigarette smoking and knee pain risk in current smokers, ever smokers, and past smokers.The major limitation of this meta-analysis relates to the heterogeneities across included studies.Cigarette smoking was associated with increased risk of CMP. In view of the high prevalence of smoking in many countries and the increasing number of CMP patients worldwide, reducing tobacco use should be an important public health strategy to prevent and control the global epidemic of CMP. Future research should attempt to establish whether this association is causal and clarify its mechanisms.

The core elements of urban carbon emission mitigation optimization path include structural adjustment, low energy supply, technological innovation, and enhanced energy demand management and improvement. How to optimize the combination of these factors to achieve the city’s emission mitigation goals at the lowest cost is very important to study the path of urban low-carbon development. Due to many factors involved, it is difficult to solve this problem by building a mathematical optimization model that includes all the elements. This paper minimizes the total cost of emission mitigations in various departments in Shenzhen, combines the uncertainty of parameters and constraints, and uses mathematically standardized method to establish a stochastic optimization model for urban carbon emissions paths. Considering the uncertainty of energy demand, the optimal promotion rate of technical measures of the city’s various departments in the stochastic optimization model during the planning period can be obtained, and the optimal solution of the city’s low-carbon development optimization path can be formed.

The Fe–Ni–Cr alloy is a potential material as bipolar plate for PEMFC (proton exchange membrane fuel cell), and the stamped metallic bipolar plate is a promising candidate instead of traditional graphite due to the advantages of mass production, low cost and excellent performance. The flow-field geometrical dimensions and the operating conditions of the stamp forming have vital influences on the formability of the alloy plate during the stamping process. Therefore, the aim of this study is to investigate the performance of the Fe–Ni–Cr alloy during the stamping process so as to optimize the flow channel dimensions. Effects of channel dimensions and operating conditions on the formability of Fe–Ni–Cr alloy performance are analyzed by numerical simulation method. Furthermore, experiments are conducted to validate the dimension accuracy of numerical methods. The results demonstrate excellent agreement between the experimental and numerical method.

The virtual reality technology is utilized to establish a typical refinery enterprise storage tank yard accident simulation system, which is designed with functions such as hazard identification, risk evaluation and analysis, typical accident simulation, typical accident emergency rescue drill, typical accident backtracking, etc. The training mode based on virtual simulation fully embodies the difficulty and risk of works and accident rescue in storage tank yards, so it is adopted to enhance trainees ability to conduct correct operations at complicated sites, reinforce their operating skills, lift their professional levels and mental adaptive ability, increase their efficiency in handling complicated dangers, and make them adapt to their jobs as early as possible. With friendly human-computer interaction interface, support of professional database, and perfect functions, the system can be used as a learning tool and drilling platform for trainees.

In this thesis, On the base of using virtual reality technology to establish the corresponding factory building virtual environment of the existing nuclear power plant. Research and development set data monitoring and fault analysis as a whole, and provide operation and maintenance support, equipment management, fault analysis, maintenance demonstration, intelligent simulation training intelligent nuclear power immersive system. To achieve 3D virtual simulation of nuclear power real-time data and equipment synchronization operation. Simulation fault state, fault analysis, real-time monitoring of test data, process alarm, remote controls in the process of production and operation. The system has the equipment 3D management, 3D fault analysis, 3D maintenance deduction, 3D intelligent simulation training and other functions.

Stainless steel 304 (SS304) is a potential material as the bipolar plate for PEMFC (proton exchange membrane fuel cell). However, its interfacial contact resistance is too high and the corrosion resistance is too low to survive in the hostile environment. A novel approach of preparing the composite coating layers by in-situ method is reported in this manuscript. The plate is first treated in acid solution, and then heat treated at low temperature, finally it is treated by electrochemical method. The ICR (interfacial contact resistance) for the treated plate is 9.8 mΩ cm 2 at the compaction force of 240 N cm −2 , and the corrosion current density is 3 × 10 −7 A cm −2 . Microstructures for differential treatments have been analyzed by FESEM (field emission scanning electron microscope), XPS (X-ray photoelectron spectroscopy) and AES (Auger electron spectroscopy). The results indicate that a protectively layer with Cr 2 O 3 /carbon is formed on the SS304 surface, which improves the performance of bipolar plate effectively.

Flow channel in bipolar plate for PEMFC has the function of transporting the fuel and oxygen and water. Stamping process for flow channel on metallic bipolar plates is an economic and convenient method for mass production. It is extremely important to predict and prevent the tearing, wrinkling, thinning, skid mark and spring back in stamping process. In this study, finite element method is used to predict the imperfection and analyze thickness variation during the stamping process. Dynaform software is employed to predict the performance of a stamping process. Forming Limit Diagrams are used to determine the safe limit of the metallic bipolar plates. In simulation, the dimension of flow channels, punch speed, radius of punch and die and draft angle were selected as variable process parameters. Experiments were conducted to compare with the simulation results. It is demonstrated that the simulation results are in good agreement with the experimental ones for ss304 metal sheets. So simulation model could be employed as a predictive tool to provide optimal parameters for better performance of the stamping process.

The tumorigenic potential of human pluripotent stem cells (hPSCs) is a major limitation to the widespread use of hPSC derivatives in the clinic. Here, we demonstrate that the small molecule STF-31 is effective at eliminating undifferentiated hPSCs across a broad range of cell culture conditions with important advantages over previously described methods that target metabolic processes. Although STF-31 was originally described as an inhibitor of glucose transporter 1, these data support the reclassification of STF-31 as a specific NAD+ salvage pathway inhibitor through the inhibition of nicotinamide phosphoribosyltransferase (NAMPT). These findings demonstrate the importance of an NAD+ salvage pathway in hPSC biology and describe how inhibition of NAMPT can effectively eliminate hPSCs from culture. These results will advance and accelerate the development of safe, clinically relevant hPSC-derived cell-based therapies. Significance The tumorigenic potential of human pluripotent stem cells (hPSCs) is a major limitation to the widespread use of hPSC derivatives in the clinic. This study provides detailed analyses of cellular metabolic flux to define an efficient strategy for selective hPSC elimination that is effective across many culture conditions and does not have cytotoxic effects on hPSC-derived progeny. Of broad significance to the stem cell and regenerative medicine fields, this study also highlights the importance of examining the effect of in vitro culturing parameters when evaluating the efficacy of hPSC-elimination strategies, especially those that target metabolic processes.

How memory T cells are maintained in vivo is poorly understood. To address this problem, a male-specific peptide (H-Y) was identified and used to activate female anti-H-Y T cells in vitro. Anti-H-Y T cells survived in vivo for at least 70 days in the absence of antigen. This persistence was not because of the intrinsic ability of memory T cells to survive in vivo . Instead, the survival and function of adoptively transferred memory cells was found to require transporter of antigen protein 1-dependent expression of self-peptide/major histocompatibility complex class I molecules in recipient animals. Therefore, it appears that the level of T cell receptor engagement provided by transporter of antigen protein 1-dependent, self-peptide/major histocompatibility complexes is sufficient to maintain the long-term survival and functional phenotype of memory cells in the absence of persistent antigen. These data suggest that positive selection plays a role not only in T cell development but also in the maintenance of T cell memory.

To understand how thymic selection gives rise to T cells that are capable of major histocompatibility complex (MHC)–restricted recognition of antigen but are tolerant of self, we directly examined how peptide/MHC ligands expressed on thymic epithelial cells trigger the positive selection of immature thymocytes. We demonstrate that abundant self-peptides, purified from the H-2D b molecules of thymic epithelial cells, are specifically recognized during the positive selection of CD8 + T cells, implying that positive selection generates a repertoire of T cells that is weakly self-reactive. We also found that this recognition is somewhat cross-reactive, thereby providing an explanation for how the specific recognition of a limited repertoire of thymic self-peptides can select a diverse repertoire of T cells.

Experiments with synthetic antigen peptides have suggested that a critical parameter that determines the developmental fate of an immature thymocyte is the affinity of interaction between TCR and self-peptide/MHC expressed on thymic stromal cells. To test the physiological relevance of this model for thymocyte development, we determined the affinity of the anti-HY TCR (B6.2.16) expressed on CD8(+) cells for thymic self-peptide/H-2D(b) tetramers, then examined the ability of these self-peptides to determine the outcome of B6.2.16 CD8 cell selection in the thymus. The B6.2.16 TCR bound the male HY self-antigen with high affinity. Thymic self-peptides, which are highly abundant on the surface of thymic epithelial cells, bound the B6.2.16 TCR with low affinity. The ability of self-peptides to trigger positive or negative selection of B6.2.16 CD8 cells in cultured fetal thymi was determined by the relative affinity of self-peptide/H-2D(b) for the B6.2.16 TCR. High-affinity binding of the HY self-peptide resulted in B6.2.16 TCR complex zeta chain phosphorylation and the negative selection of B6.2.16 CD8 cells. Low-affinity binding of thymic self-peptides to B6.2.16 TCR resulted in the positive selection of B6.2.16 CD8 cells. Differences between the binding affinities of self-peptides to B6.2.16 TCR accounted for the self-peptide specificity of B6.2.16 CD8 cell positive selection. We conclude that the relative affinity of TCR for thymic self-peptide/class I MHC is a critical parameter in determining fate of CD8(+) cells during thymic selection.

We have investigated the spectroscopic properties of two classes of light-harvesting 2 (LH2, B800-850) mutants of Rhodobacter capsulatus obtained by combinatorial mutagenesis to the C-terminal half of the beta-apoprotein: a pseudoLH2 (pLH2) class, in which the 800-nm absorption was normal but the 850-nm peak was blue-shifted by up to 14 nm, and the other a pseudoLH1 (pLH1) class, which lacked the 800-nm absorption band and showed 850-nm absorption red-shifts of up to 30 nm. In several of the pLH1 antennae, carotenoid depletion contributed to the phenotype, while in the pLH2 complexes there was some carotenoid enrichment. A number of mutants from each class have also been characterized by low-temperature absorption and fluorescence spectroscopy, resonance Raman spectroscopy, and circular dichroism. In all of the mutants investigated, the B850 bacteriochlorophyll a binding site remained intact, conserving both the hydrogen bonding environment of the chromophores and their conformation and liganding. In contrast, the intensity of the CD spectra of pLH1 complexes was considerably reduced, relative to that of wild-type or pLH2 complexes, consistent with alterations in the interactions between pigments and in their relative orientation. Elevated fluorescence polarization over the red wing of the B850 band in the pLH2 complexes indicated a reduction of exciton mobility within the ring of BChl molecules. Possible structural alterations governing the spectral properties of the different mutants are discussed.

The light-harvesting 2 (LH2, B800–850) complex of the proteobacterium Rhodobacter capsulatus is a bacteriochlorophyll a (BChl) binding, integral membrane protein that serves as a peripheral antenna, directing collected excitations to the cores of photosynthetic units which consist of LH1 and reaction center complexes. The R. capsulatus LH2 complex is a heterodimer of conserved α- and β-polypeptides (7.3 and 5.1 kDa, respectively), which bind a BChl dimer (B850) absorbing near 850 nm, a monomeric BChl (B800) absorbing at 800 nm and one to two carotenoids, as well as a 14-kDa γ-subunit [1]. Recently, considerable interest in the LH2 protein has arisen from the determination of the three-dimensional structure of the homologous LH2 complex of Rhodopseudomonas acidophila by X-ray crystallography [2]. The overall structure forms a cylinder in which the transmembrane helices of nine β- and nine α-apoproteins make up the respective outer and inner walls. A ring of 18 B850 BChls, with overlapping bacteriochlorin moieties, is sandwiched between them, while the nine B800 BChls are positioned between the outer helices. A carotenoid is seen intertwined with the phytol chains of the BChls, nearly spanning the membrane. Despite this major structural advance, the main factors controlling the absorption of the antennae of purple bacteria are not well understood, particularly those distinguishing an LH1-like from an LH2-like complex. Characterization of the set of mutants of the R. capsulatus LH2 protein described here, has provided an opportunity to shed more light on this question.

The photoreceptor complex (B885-RC) and the peripheral antenna complex (B800-860) were isolated from photosynthetic membranes of the purple non-sulfur bacterium Rhodocyclus tenuis DSM 109 using a detergent combination of Deriphate-160 and octyl glucoside and subsequent linear sucrose gradient centrifugation. The two complexes were characterized by room-temperature absorption, circular dichroism and fluorescence spectroscopy. The B800-860 complex has a more red-shifted B860 absorbance band. The alpha,beta-polypeptides were purified with a reverse-phase HPLC system and resolved at a ratio of 1:1 in the B800-860 complex and at an overall ratio of 1:1 for the B885-RC complex. The complete amino acid sequences of the alpha and beta polypeptides of the B800-860 and B885-RC complexes were determined by micro-sequencing analysis and mass spectrometry. The B800-860-alpha polypeptide possesses an identical N-terminal domain (the first 15 residues) to Rhodobacter sphaeroides B800-850-alpha polypeptide. The central hydrophobic and C-terminal domains of the B800-860-alpha,beta polypeptides show a number of B870/880-like structural elements in which, of special interest, is the WWSEF cluster in the C-terminal domain of the B800-860-alpha polypeptide which is very similar to the WWEF cluster in the same region of Rhodopseudomonas viridis B1015-alpha polypeptide. The more red-shifted absorption characteristic of the 860-nm bacteriochlorophylls could most probably be related to the B870/880-like polypeptide features in the central hydrophobic domains and the C-terminal domains of the B800-860-alpha,beta polypeptides. The hydropathy plot of the B800-860-alpha polypeptide exhibits an extended C-terminal hydrophobic segment indicative of a second membrane-contacting domain, which has not been found in the antenna polypeptides of the purple bacteria with intracytoplasmic membranes. Further sequence analysis revealed the existence of multiple forms of the B885-alpha,beta polypeptides, the B885-alpha 1,alpha 2 polypeptides, and the B885-beta 1,beta 2 polypeptides. The B885-Alpha 2 polypeptide shows an identical sequence to the B885-alpha 1 polypeptide, but it is 12 amino acid residues shorter than the B885-alpha 1 polypeptide at the C-terminal. The two species of the B885-beta polypeptides were identified as an identical sequence with only one amino acid residue variation at sequence position 34, where the B885-beta 1 has a valine residue and the B885-beta 2 polypeptide an isoleucine residue. The possible correlation between the intensity of the near-infrared circular dichroic signal and the specific structural features of the alpha and beta core antenna polypeptides is also discussed.