Structure of a unique PSII-Pcb tetrameric megacomplex in a chlorophyll d-containing cyanobacterium

Acaryochloris marina is a unique cyanobacterium using chlorophyll d (Chl d) as its major pigment and thus can use far-red light for photosynthesis. Photosystem II (PSII) of A. marina associates with a number of prochlorophyte Chl-binding (Pcb) proteins to act as the light-harvesting system. We report here the cryo-electron microscopic structure of a PSII-Pcb megacomplex from A. marina at a 3.6-angstrom overall resolution and a 3.3-angstrom local resolution. The megacomplex is organized as a tetramer consisting of two PSII core dimers flanked by sixteen symmetrically related Pcb proteins, with a total molecular weight of 1.9 megadaltons. The structure reveals the detailed organization of PSII core consisting of 15 known protein subunits and an unknown subunit, the assembly of 4 Pcb antennas within each PSII monomer, and possible pathways of energy transfer within the megacomplex, providing deep insights into energy transfer and dissipation mechanisms within the PSII-Pcb megacomplex involved in far-red light utilization.

Cyclometalated gold(III)-hydride under oriented external electric fields: a new strategy to modulate its reactivity?

Selected gold complexes have been regarded as promising anti-cancer agents because they can bind with protein targets containing thiol or selenol moieties, but their clinical applications were hindered by the unbiased binding towards off-target thiol-proteins. Recently, a novel gold(III)-hydride complex (abbreviated as 1) with visible light-induced thiol reactivity has been reported as potent photo-activated anticancer agents (Angew. Chem. Int. Ed., 2020, 132, 11139). To explore new strategies to stimuli this potential antitumor drug, the effect of oriented external electric fields (OEEFs) on its geometric structure, electronic properties, and chemical reactivity was systematically investigated. Results reveal that imposing external electric fields along the Au-H bond of 1 can effectively activate this bond, which is conducive to its dissociation and the binding of Au site to potential targets. Hence, this study provides a new OEEF-strategy to activate this reported gold(III)-hydride, revealing its potential application in electrochemical therapy. We anticipate this work could promote the development of more electric field-activated anticancer agents. However, further experimental research should be conducted to verify the conclusions obtained in this work.

Surgical treatment of nasopharyngeal cancer - a consensus recommendation from two Chinese associations

BACKGROUND

Surgical treatment is playing an increasingly important role in the management of nasopharyngeal carcinoma (NPC). This consensus focuses on the indications for optimal surgery, and surgical methods in the whole process of treatment for NPC to provide a useful reference to assist these difficult clinical decisions.

METHODOLOGY

A thorough review of available literature on NPC and surgery was conducted by the Association for the prevention and treatment of nasopharyngeal carcinoma in China, international exchange and promotion Association for medicine and healthcare, and the Committee on nasopharyngeal cancer of Guangdong provincial anticancer association. A set of questions and a preliminary draft guideline was circulated to a panel of 1096 experienced specialists on this disease for voting on controversial areas and comments. A refined second proposal, based on a summary of the initial voting and different opinions expressed, was recirculated to the experts in two authoritative medical science and technology academic groups in the prevention and treatment of NPC in China for review and reconsideration.

RESULTS

The initial round of questions showed variations in clinical practice even among similar specialists, reflecting the lack of high-quality supporting data and resulting difficulties in formulating clinical decisions. Through exchange of comments and iterative revisions, recommendations with high-to-moderate agreement were formulated on general treatment strategies and details of surgery, including indications and surgical approaches.

CONCLUSION

By standardizing the surgical indications and practice, we hope not only to improve the surgical outcomes, but also to highlight the key directions of future clinical research in the surgical management of NPC.

Theoretical prediction of superatom WSi12-based catalysts for CO oxidation by N2O

Catalytic conversion of N2O and CO into nonharmful gases is of great significance to reduce their adverse impact on the environment. The potential of the WSi12 superatom to serve as a new cluster catalyst for CO oxidation by N2O is examined for the first time. It is found that WSi12 prefers to adsorb the N2O molecule rather than the CO molecule, and the charge transfer from WSi12 to N2O results in the full activation of N2O into a physically absorbed N2 molecule and an activated oxygen atom that is attached to an edge of the hexagonal prism structure of WSi12. After the release of N2, the remaining oxygen atom can oxidize one CO molecule via overcoming a rate-limiting barrier of 28.19 kcal mol-1. By replacing the central W atom with Cr and Mo, the resulting MSi12 (M = Cr and Mo) superatoms exhibit catalytic performance for CO oxidation comparable to the parent WSi12. In particular, the catalytic ability of WSi12 for CO oxidation is well maintained when it is extended into tube-like WnSi6(n+1) (n = 2, 4, and 6) clusters with energy barriers of 25.63-29.50 kcal mol-1. Moreover, all these studied MSi12 (M = Cr, Mo, and W) and WnSi6(n+1) (n = 2, 4, and 6) species have high structural stability and can absorb sunlight to drive the catalytic process. This study not only opens a new door for the atomically precise design of new silicon-based nanoscale catalysts for various chemical reactions but also provides useful atomic-scale insights into the size effect of such catalysts in heterogeneous catalysis.

Enhanced Bonding to Caries-Affected Dentin Using an Isocyanate-Based Primer

Dental caries is the most common oral disease and the most common cause of resin restorations. In minimally invasive dentistry, the principle behind cavity preparation is to remove external caries-infected dentin (CID) and preserve internal caries-affected dentin (CAD) and sound dentin (SD). The cavity floor is mainly composed of CAD, but the poor bonding performance of CAD has become a widespread concern. This study evaluated the performance of a new collagen-reactive monomer (ITCM) used as a primer to improve the bonding performance of CAD. The experimental specimens were grouped as follows: SD, CAD, and ITCM-pretreated CAD (CAD-ITCM). Dentin slices were obtained for attenuated total reflectance-Fourier transform infrared (ATR-FTIR) analysis. The bonded samples were subjected to microtensile bond strength analysis after 24 h of water storage or aging by thermocycling, and the bonding interface quality was evaluated by nanoleakage assessment, interfacial nanoindentation testing, and in situ zymography. Cytotoxicity experiments with ITCM were performed. ATR-FTIR showed that the isocyanate groups in ITCM can covalently bind and form hydrogen bonds with the collagen in CAD to mediate chemical bonding. ITCM pretreatment significantly improved the bond strength of CAD (P < 0.05), reduced interfacial nanoleakage, improved the sealing of the bonding interface, enhanced the homogeneity of the hybrid layer, and inhibited matrix metalloproteinase activity. In addition, ITCM presented acceptable biocompatibility for dental restorative application. Taken together, this study reported the application of ITCM to induce collagen-based chemical bonding in the CAD bonding system, which fills the gap in strategies to improve the bonding performance of CAD immediately and after aging and has important clinical application prospects.

Computational screening of metalloporphyrin-based drug carriers for antitumor drug 5-fluorouracil

Developing novel nanoscale carriers for drug delivery is of great significance for improving treatment efficiency and reducing side effects of antitumor drugs. In view of the good biocompatibility and special affinity of porphyrin (PP) molecule to cancer cells, it was used to construct a series of metal-doped M@PP (M = Ca ∼ Zn) materials for the delivery of anticancer drug 5-fluorouracil (5-Fu) in this work. Our results reveal that 5-Fu is tightly adsorbed on M@PP (M = Ca ∼ V, Mn ∼ Co, and Zn) by chemisorption, but is physically adsorbed by M@PP (M = Cr, Ni, and Cu). The calculated electronic properties show that all these 5-Fu@[M@PP] (M = Ca ∼ Zn) complexes have both high stability and solubility. Among these 5-Fu@[M@PP] complexes, the chemical bond formed between 5-Fu and Ti@PP has the strongest covalent characteristic, resulting in the largest adsorption energy of -19.93 kcal/mol for 5-Fu@[Ti@PP]. In particular, 5-Fu@[Ti@PP] has the proper recovery time under the near-infrared light at body temperature, which further suggests that Ti@PP is the best drug carrier for 5-Fu. This study not only reveals the interaction strength and nature between 5-Fu and M@PP, but also confirmed the intriguing potential of Ti@PP as nano-carrier for drug delivery. However, further experimental research should be conducted to verify the conclusion obtained in this work.

Hyperon Polarization along the Beam Direction Relative to the Second and Third Harmonic Event Planes in Isobar Collisions at sqrt[s_{NN}]=200 GeV

The polarization of Λ and Λ[over ¯] hyperons along the beam direction has been measured relative to the second and third harmonic event planes in isobar Ru+Ru and Zr+Zr collisions at sqrt[s_{NN}]=200  GeV. This is the first experimental evidence of the hyperon polarization by the triangular flow originating from the initial density fluctuations. The amplitudes of the sine modulation for the second and third harmonic results are comparable in magnitude, increase from central to peripheral collisions, and show a mild p_{T} dependence. The azimuthal angle dependence of the polarization follows the vorticity pattern expected due to elliptic and triangular anisotropic flow, and qualitatively disagrees with most hydrodynamic model calculations based on thermal vorticity and shear induced contributions. The model results based on one of existing implementations of the shear contribution lead to a correct azimuthal angle dependence, but predict centrality and p_{T} dependence that still disagree with experimental measurements. Thus, our results provide stringent constraints on the thermal vorticity and shear-induced contributions to hyperon polarization. Comparison to previous measurements at RHIC and the LHC for the second-order harmonic results shows little dependence on the collision system size and collision energy.

Erratum: Global Polarization of Ξ and Ω Hyperons in Au+Au Collisions at sqrt[s_{NN}]=200 GeV [Phys. Rev. Lett. 126, 162301 (2021)]

This corrects the article DOI: 10.1103/PhysRevLett.126.162301.

[Short-term outcome of patients after transcatheter aortic valve replacement receiving different anticoagulants]

Objective: To compare the safety and efficacy of different anticoagulants in patients with indications for anticoagulation after transcatheter aortic valve replacement (TAVR). Methods: This is a retrospective study. Patients who underwent TAVR from April 2016 to February 2022 in Guangdong Provincial People's Hospital and had indications for anticoagulation were included and divided into two groups according to the type of anticoagulants, i.e. non-vitamin K antagonist oral anticoagulant (NOAC) and warfarin, and patients were followed up for 30 days. The primary endpoint was the combination of death, stroke, myocardial infarction, valve thrombosis, intracardiac thrombosis and major bleeding. The incidence of endpoints was compared between two groups, and multivariate logistic regression analysis was applied to adjust the bias of potential confounders. Results: A total of 80 patients were included. Mean age was (74.4±7.1) years, 43 (53.8%) were male. Forty-nine (61.3%) patients used NOAC, 31 used warfarin, and major indication for anticoagulants was atrial fibrillation (76/80, 95.0%). The adjusted risks of the primary endpoint (OR=0.23, 95%CI 0.06-0.94, P=0.040) of NOAC were lower than that of warfarin, mainly driven by a lower risk of major bleeding (OR=0.19, 95%CI 0.04-0.92, P=0.039). Conclusions: The short-term outcome of NOAC is better than that of warfarin in patients with indications for anticoagulation after TAVR. Randomized controlled trials of large sample size with long-term follow-up are needed to further testify this finding.

Measurements of the Elliptic and Triangular Azimuthal Anisotropies in Central ^{3}He+Au, d+Au and p+Au Collisions at sqrt[s_{NN}]=200 GeV

The elliptic (v_{2}) and triangular (v_{3}) azimuthal anisotropy coefficients in central ^{3}He+Au, d+Au, and p+Au collisions at sqrt[s_{NN}]=200  GeV are measured as a function of transverse momentum (p_{T}) at midrapidity (|η|<0.9), via the azimuthal angular correlation between two particles both at |η|<0.9. While the v_{2}(p_{T}) values depend on the colliding systems, the v_{3}(p_{T}) values are system independent within the uncertainties, suggesting an influence on eccentricity from subnucleonic fluctuations in these small-sized systems. These results also provide stringent constraints for the hydrodynamic modeling of these systems.

Observation of Directed Flow of Hypernuclei _{Λ}^{3}H and _{Λ}^{4}H in sqrt[s_{NN}]=3 GeV Au+Au Collisions at RHIC

We report here the first observation of directed flow (v_{1}) of the hypernuclei _{Λ}^{3}H and _{Λ}^{4}H in mid-central Au+Au collisions at sqrt[s_{NN}]=3  GeV at RHIC. These data are taken as part of the beam energy scan program carried out by the STAR experiment. From 165×10^{6} events in 5%-40% centrality, about 8400 _{Λ}^{3}H and 5200 _{Λ}^{4}H candidates are reconstructed through two- and three-body decay channels. We observe that these hypernuclei exhibit significant directed flow. Comparing to that of light nuclei, it is found that the midrapidity v_{1} slopes of _{Λ}^{3}H and _{Λ}^{4}H follow baryon number scaling, implying that the coalescence is the dominant mechanism for these hypernuclei production in the 3 GeV Au+Au collisions.

Beam Energy Dependence of Triton Production and Yield Ratio (N_{t}×N_{p}/N_{d}^{2}) in Au+Au Collisions at RHIC

We report the triton (t) production in midrapidity (|y|<0.5) Au+Au collisions at sqrt[s_{NN}]=7.7-200  GeV measured by the STAR experiment from the first phase of the beam energy scan at the Relativistic Heavy Ion Collider. The nuclear compound yield ratio (N_{t}×N_{p}/N_{d}^{2}), which is predicted to be sensitive to the fluctuation of local neutron density, is observed to decrease monotonically with increasing charged-particle multiplicity (dN_{ch}/dη) and follows a scaling behavior. The dN_{ch}/dη dependence of the yield ratio is compared to calculations from coalescence and thermal models. Enhancements in the yield ratios relative to the coalescence baseline are observed in the 0%-10% most central collisions at 19.6 and 27 GeV, with a significance of 2.3σ and 3.4σ, respectively, giving a combined significance of 4.1σ. The enhancements are not observed in peripheral collisions or model calculations without critical fluctuation, and decreases with a smaller p_{T} acceptance. The physics implications of these results on the QCD phase structure and the production mechanism of light nuclei in heavy-ion collisions are discussed.

Measurement of Sequential ϒ Suppression in Au+Au Collisions at sqrt[s_{NN}]=200 GeV with the STAR Experiment

We report on measurements of sequential ϒ suppression in Au+Au collisions at sqrt[s_{NN}]=200  GeV with the STAR detector at the Relativistic Heavy Ion Collider (RHIC) through both the dielectron and dimuon decay channels. In the 0%-60% centrality class, the nuclear modification factors (R_{AA}), which quantify the level of yield suppression in heavy-ion collisions compared to p+p collisions, for ϒ(1S) and ϒ(2S) are 0.40±0.03(stat)±0.03(sys)±0.09(norm) and 0.26±0.08(stat)±0.02(sys)±0.06(norm), respectively, while the upper limit of the ϒ(3S) R_{AA} is 0.17 at a 95% confidence level. This provides experimental evidence that the ϒ(3S) is significantly more suppressed than the ϒ(1S) at RHIC. The level of suppression for ϒ(1S) is comparable to that observed at the much higher collision energy at the Large Hadron Collider. These results point to the creation of a medium at RHIC whose temperature is sufficiently high to strongly suppress excited ϒ states.

Beam Energy Dependence of Fifth- and Sixth-Order Net-Proton Number Fluctuations in Au+Au Collisions at RHIC

We report the beam energy and collision centrality dependence of fifth and sixth order cumulants (C_{5}, C_{6}) and factorial cumulants (κ_{5}, κ_{6}) of net-proton and proton number distributions, from center-of-mass energy (sqrt[s_{NN}]) 3 GeV to 200 GeV Au+Au collisions at RHIC. Cumulant ratios of net-proton (taken as proxy for net-baryon) distributions generally follow the hierarchy expected from QCD thermodynamics, except for the case of collisions at 3 GeV. The measured values of C_{6}/C_{2} for 0%-40% centrality collisions show progressively negative trend with decreasing energy, while it is positive for the lowest energy studied. These observed negative signs are consistent with QCD calculations (for baryon chemical potential, μ_{B}≤110  MeV) which contains the crossover transition range. In addition, for energies above 7.7 GeV, the measured proton κ_{n}, within uncertainties, does not support the two-component (Poisson+binomial) shape of proton number distributions that would be expected from a first-order phase transition. Taken in combination, the hyperorder proton number fluctuations suggest that the structure of QCD matter at high baryon density, μ_{B}∼750  MeV at sqrt[s_{NN}]=3  GeV is starkly different from those at vanishing μ_{B}∼24  MeV at sqrt[s_{NN}]=200  GeV and higher collision energies.

[Safety and efficacy of laparoscopic surgery in locally advanced gastric cancer patients with neoadjuvant chemotherapy combined with immunotherapy]

Objective: To investigate the safety and efficacy of laparoscopic surgery in locally advanced gastric cancer patients with neoadjuvant SOX chemotherapy combined with PD-1 inhibitor immunotherapy. Methods: Between November 2020 and April 2021, patients with locally advanced gastric cancer who were admitted to the Union Hospital of Tongji Medical College of Huazhong University of Science and Technology were prospectively enrolled in this study. Inclusion criteria were: (1) patients who signed the informed consent form voluntarily before participating in the study; (2) age ranging from 18 to 75 years; (3) patients staged preoperatively as cT3-4N+M0 by the TNM staging system; (4) Eastern Collaborative Oncology Group score of 0-1; (5) estimated survival of more than 6 months, with the possibility of performing R0 resection for curative purposes; (6) sufficient organ and bone marrow function within 7 days before enrollment; and (7) complete gastric D2 radical surgery. Exclusion criteria were: (1) history of anti-PD-1 or PD-L1 antibody therapy and chemotherapy; (2) treatment with corticosteroids or other immunosuppre- ssants within 14 days before enrollment; (3) active period of autoimmune disease or interstitial pneumonia; (4) history of other malignant tumors; (5) surgery performed within 28 days before enrollment; and (6) allergy to the drug ingredients of the study. Follow-up was conducted by outpatient and telephone methods. During preoperative SOX chemotherapy combined with PD-1 inhibitor immunotherapy, follow-up was conducted every 3 weeks to understand the occurrence of adverse reactions of the patients; follow-up was conducted once after 1 month of surgical treatment to understand the adverse reactions and survival of patients. Observation indicators were: (1) condition of enrolled patients; (2) reassessment after preoperative therapy and operation received (3) postoperative conditions and pathological results. Evaluation criteria were: (1) tumor staged according to the 8th edition of the American Joint Committee on Cancer (AJCC) TNM staging system; (2) tumor regression grading (TRG) of pathological results were evaluated with reference to AJCC standards; (3) treatment-related adverse reactions were evaluated according to version 5.0 of the Common Terminology Criteria for Adverse Events; (4) tumor response was evaluated by CT before and after treatment with RECIST V1.1 criteria; and (5) Clavien-Dindo complication grading system was used for postoperative complications assessment. Results: A total of 30 eligible patients were included. There were 25 males and 5 females with a median age of 60.5 (35-74) years. The primary tumor was located in the gastroesophageal junction in 12 cases, in the upper stomach in 8, in the middle stomach in 7, and in the lower stomach in 3. The preoperative clinical stage of 30 cases was III. Twenty-one patients experienced adverse reactions during neoadjuvant chemotherapy combined with immunotherapy, including four cases of CTCAE grade 3-4 adverse reactions resulting in bone marrow suppression and thoracic aortic thrombosis. All cases of adverse reactions were alleviated or disappeared after active symptomatic treatment. Among the 30 patients who underwent surgery, the time from chemotherapy combined with immunotherapy to surgery was 28 (23-49) days. All 30 patients underwent laparoscopic radical gastrectomy, of which 20 patients underwent laparoscopic-assisted radical gastric cancer resection; 10 patients underwent total gastrectomy for gastric cancer, combined with splenectomy in 1 case and cholecystectomy in 1 case. The surgery time was (239.9±67.0) min, intraoperative blood loss was 84 (10-400) ml, and the length of the incision was 7 (3-12) cm. The degree of adenocarcinoma was poorly differentiated in 18 cases, moderately differentiated in 12 cases, nerve invasion in 11 cases, and vascular invasion in 6 cases. The number lymph nodes that underwent dissection was 30 (17-58). The first of gas passage, the first postoperative defecation time, the postoperative liquid diet time, and the postoperative hospitalization time of 30 patients was 3 (2-6) d, 3 (2-13) d, 5 (3-12) d, and 10 (7-27) d, respectively. Postoperative complications occurred in 23 of 30 patients, including 7 cases of complications of Clavien-Dindo grade IIIa or above. Six patients improved after treatment and were discharged from hospital, while 1 patient died 27 days after surgery due to granulocyte deficiency, anemia, bilateral lung infection, and respiratory distress syndrome. The remaining 29 patients had no surgery-related morbidity or mortality within 30 days of discharge. Postoperative pathological examination showed TRG grades 0, 1, 2, and 3 in 8, 9, 4, and 9 cases, respectively, and the number of postoperative pathological TNM stages 0, I, II, and III was 8, 7, 8, and 7 cases, respectively. The pCR rate was 25.0% (8/32). Conclusion: Laparoscopic surgery after neoadjuvant SOX chemotherapy combined with PD-1 inhibitor immunotherapy for locally advanced gastric cancer is safe and feasible, with satisfactory short-term efficacy. Early detection and timely treatment of related complications are important.

On the possibility of using the Ti@Si16 superatom as a novel drug delivery carrier for different drugs: A DFT study

The potential application of an experimentally synthesized superatom Ti@Si₁₆ as a novel drug carrier for cisplatin (DDP), isoniazid (INH), acetylsalicylic acid (ASA), 5-fluorouracil (5-Fu), and favipiravir (FPV) has been explored by density functional theory. It is observed that the Pt atom of DDP can be effectively absorbed on Ti@Si₁₆ via a "donation-back donation" electron transfer mechanism, resulting in a moderate adsorption energy of -19.95 kcal/mol for DDP@[Ti@Si₁₆]. As for INH, it prefers to combine with Ti@Si₁₆ via the N atom of pyridine ring by forming a strongly polar N-Si bond. Differently, the interaction between Ti@Si₁₆ and the ASA, 5-Fu, and FPV drugs is dominated by the Van der Waals interaction. Our results reveal that DDP@[Ti@Si₁₆] possesses a moderate recovery time under body temperature, which benefits the desorption of DDP from Ti@Si₁₆. More importantly, the release of DDP drug from the Ti@Si₁₆ surface can be effectively controlled by exerting small orientation external electric fields on the DDP@[Ti@Si₁₆] complex. Therefore, this study demonstrates that Ti@Si₁₆ can serve as a promising drug carrier for DDP, and thus will further expand its practical applications in the biomedical field.

Cryo-electron microscopy structure of the intact photosynthetic light-harvesting antenna-reaction center complex from a green sulfur bacterium

The photosynthetic reaction center complex (RCC) of green sulfur bacteria (GSB) consists of the membrane-imbedded RC core and the peripheric energy transmitting proteins called Fenna-Matthews-Olson (FMO). Functionally, FMO transfers the absorbed energy from a huge peripheral light-harvesting antenna named chlorosome to the RC core where charge separation occurs. In vivo, one RC was found to bind two FMOs, however, the intact structure of RCC as well as the energy transfer mechanism within RCC remain to be clarified. Here we report a structure of intact RCC which contains a RC core and two FMO trimers from a thermophilic green sulfur bacterium Chlorobaculum tepidum at 2.9 Å resolution by cryo-electron microscopy. The second FMO trimer is attached at the cytoplasmic side asymmetrically relative to the first FMO trimer reported previously. We also observed two new subunits (PscE and PscF) and the N-terminal transmembrane domain of a cytochrome-containing subunit (PscC) in the structure. These two novel subunits possibly function to facilitate the binding of FMOs to RC core and to stabilize the whole complex. A new bacteriochlorophyll (numbered as 816) was identified at the interspace between PscF and PscA-1, causing an asymmetrical energy transfer from the two FMO trimers to RC core. Based on the structure, we propose an energy transfer network within this photosynthetic apparatus.

Collision-System and Beam-Energy Dependence of Anisotropic Flow Fluctuations

Elliptic flow measurements from two-, four-, and six-particle correlations are used to investigate flow fluctuations in collisions of U+U at sqrt[s_{NN}]=193  GeV, Cu+Au at sqrt[s_{NN}]=200  GeV and Au+Au spanning the range sqrt[s_{NN}]=11.5-200  GeV. The measurements show a strong dependence of the flow fluctuations on collision centrality, a modest dependence on system size, and very little if any, dependence on particle species and beam energy. The results, when compared to similar LHC measurements, viscous hydrodynamic calculations, and trento model eccentricities, indicate that initial-state-driven fluctuations predominate the flow fluctuations generated in the collisions studied.

[Dynamic analysis of tuberculosis specific mononuclear cells in peripheral blood of HIV patients with tuberculosis]

Objective: To evaluate the response of peripheral blood mononuclear cells (PBMCs) in patients with human immunodeficiency virus (HIV) combined with active tuberculosis (TB) to TB-specific antigen stimulation. Methods: From January to December, 2018, individuals infected with both HIV and TB (HIV/TB group) were taken as the study subjects. Individuals infected with HIV alone (HIV group), individuals infected with TB alone (TB group) and healthy people (Health control group, HC group) were taken as the control groups. PBMCs were isolated and stimulated with purified protein derivative of bacillus calmette-guerin (BCG-PPD). The expression of surface molecules in T cells (CD3⁺, CD4⁺, CD8⁺) and monocytes (CD14⁺) and the percentages of Interferon (IFN)-γ and tumor necrosis factor (TNF)-α were detected by cell surface molecular staining, direct intracellular cytokine staining and flow cytometry (CD3^- lymphocytes were mainly B lymphocytes and NK cells). Analysis of non-parametric data was used to compare the data between the two groups, and paired t-test was used to compare the data before and after PPD stimulation in each group. Results: Before PPD stimulation, the percentage of IFN-γ⁺ CD8⁺ cells in the peripheral blood of HIV/TB group(mean 0.52%) was significantly lower than that in TB group(mean 0.94%, P=0.010). The TNF-α⁺cell percentages in CD3⁺, CD4⁺, CD8⁺, or CD14⁺ cells in the HIV/TB group(mean 19.2%) were significantly lower than those in the HIV group(mean 31.9%, P=0.002). The percentage of TNF-α secreted by monocytes in the HIV group was significantly lower than that in the HC group. The percentages of IFN-γ⁺ CD8⁺ and IFN-γ⁺ CD3^- cells in the peripheral blood of the TB group (mean 0.94%) were significantly higher than thoset in the HC group(mean 0.51%, P=0.020), while the percentages of TNF-α⁺ cells in each subsets of PBMCs were significantly lower than those in the HC group. After PPD stimulation, the percentage of IFN-γ⁺ CD8⁺ cells in the HIV/TB group was significantly lower than that in the TB group(P=0.008), and the change was more marked than that before stimulation. The percentage of IFN-γ⁺ CD8⁺ cells in the HIV group(mean 0.20%) was lower than that in the HC group (mean 0.52%, P=0.044). The percentage of IFN-γ⁺ CD3^- in the TB group was significantly higher than in the HC group. There were no significant differences in TNF-α⁺ cell percentages in the 3 groups compared with the control group after PPD stimulation. The percentages of IFN-γ⁺ CD4⁺ cells in the HC and the TB groups were significantly increased after PPD stimulation in each group (P=0.002, P=0.001, respectively). However, there were no significant differences of IFN-γ⁺ CD4⁺ cell percentages in the HIV/TB group and the HIV group. The percentages of TNF-α production by monocytes were significantly increased after PPD stimulation in all groups. Conclusions: Chronic Mycobacterium tuberculosis (MTB) infection reduced the ability of PBMCs to produce TNF-α. For patients with TB infection, the production of TNF-α was reduced when combined with HIV infection. The capacity of CD8⁺ and CD3^- lymphocytes to produce IFN-γ was increased in TB patients, while the capacity of CD8⁺ T cells to produce IFN-γ was decreased with co-infection of HIV. Infection of HIV weakened the immune response to MTB infection, which made the clinical diagnosis and treatment of TB more difficult.

Oncological outcomes of neoadjuvant chemotherapy in patients with resectable synchronous colorectal liver metastasis: A result from a propensity score matching study

Background

The efficacy and safety of neoadjuvant chemotherapy (NAC) in treating resectable synchronous colorectal liver metastases (CRLM) remain controversial.

Methods

Data from CRLM patients who underwent simultaneous liver resection between January 2015 and December 2019 were collected from the Surveillance, Epidemiology, and End Results (SEER) database (SEER cohort, n=305) and a single Chinese Cancer Center (NCC cohort, n=268). Using a 1:2 ratio of propensity score matching (PSM), the prognostic impact of NAC for patients who underwent NAC before surgical treatment and patients who underwent surgical treatment alone was evaluated.

Results

After PSM, there was no significant difference in overall survival (OS) between patients receiving NAC prior to CRLM resection and those undergoing surgery only, in both the NCC and SEER cohorts (each P &gt; 0.05). Age was an independent predictor of OS only in the SEER cohort (P = 0.040), while the pN stage was an independent predictor for OS only in the NCC cohort (P = 0.002). Furthermore, Disease-free survival (DFS) was comparable between the two groups in the NCC cohort. In a subgroup analysis, the DFS and OS in the NAC- group were significantly worse than those in the NAC+ group for patients with more than two liver metastases in the NCC cohort (P &lt; 0.05 for both).

Conclusion

NAC did not have a significant prognostic impact in patients with resectable synchronous CRLM. However, patients with more than two liver metastases could be good candidates for receiving NAC.

[Finite element analysis and biomimetic optimal design of full-crown restoration]

Objective: To improve the mechanical properties of full-crown restorations and illuminate the optimal elastic modulus distribution through bionic optimization design and finite element analysis (FEA). Methods: Seven 3D models of mandibular first premolars with different full-crown restorations were constructed: (A) zirconia monolithic crown, (B) lithium disilicate monolithic crown, (C) zirconia bilayer crown, (D) lithium disilicate bilayer crown, (E) 8-layer crown referred to the elastic modulus distribution of human enamel, (F) and (G) were 8-layer crowns with elastic modulus distribution calculated by a genetic algorithm (GA) to minimize the tensile stresses in the crown and the shear stresses at the cementing line, respectively. Results in the crowns and cementing lines were obtained with maximum principal stress after applying a static load of 600 N. Results: The principal tensile stresses in the full-crown restorations were mainly concentrated in the cervical margins and the crown-cementing interface. Among them, G exhibited a peak tensile stress of 25.79 MPa, which decreased to 17.72 MPa in E and 16.25 MPa in F; The principal shear stresses in cementing lines were concentrated along the margins and low on the axial wall. The peak shear stress of the cementing line of E and F was 11.81 MPa and 11.79 MPa, respectively. While G was found to has the lowest peak shear stress of 6.14 MPa. Conclusion: The elastic modulus distribution optimized by GA to reduce the peak shear stress of the cementing line can better improve the mechanical properties of the full-crown restoration.

[Clinical analysis of 7 children infected with Talaromyces marneffei]

Objective: To investigate the clinical manifestations, treatments, and prognosis of pediatric patients with Talaromyces marneffei infection. Methods: In this retrospective study, 7 children diagnosed with Talaromyces marneffei infection in Shenzhen Children's Hospital from July 2017 to October 2021 were recruited. The clinical features, radiology, pathogen detection, immunological evaluation, treatments, and prognosis were analyzed. Results: In 7 cases, 5 were male, 2 were females. The age was from 0.75 to 8.75 years. The main clinical manifestations were fever in 7 cases, cough in 6 cases, malnutrition in 4 cases, papules in 2 cases and medical history of recurrent infection in 3 cases. Physical examination showed that all 7 patients had hepatosplenomegaly, 4 had superficial lymphadenopathy. Laboratory examination showed that 6 cases had decreased hemoglobin and 3 cases had decreased platelet. Chest CT showed that 4 cases had patchy shadows, pleural effusion, mediastinal or axillary lymph node enlargement, 3 had nodular shadows and 2 had cavities. The positive ratio of Talaromyces marneffei culture was 2/2 with tissue samples, 4/5 with bone marrow. The positive ratio was 3/4 by metagenomic next generation sequencing. The fungus was detected in 3 cases by smear microscopy of bone marrow and (or) peripheral blood. All patients were negative for human immunodeficiency virus by the immune function assay. However, 5 cases were confirmed as primary immunodeficiency disease, including 2 cases with high IgM syndrome, 2 with STAT1 gene variation, and the last with severe combined immunodeficiency (IL2RG gene variation). Exclude 1 case which gave up treatment due to acute intracranial infection, and the other patients received effective treatments along with amphotericin B, voriconazole, and itraconazole alone or in combination. Two cases relapsed after medication withdrawal, but 1 case got complete rehabilitation after hematopoietic stem cell transplantation. Conclusions: The clinical manifestations involve multisystem, the common charateristics are fever and cough. The chest CT imaging manifestations are diverse, it should be considered in differentiating tuberculosis. The amphotericin B, voriconazole and itraconazole are effective, but it will easily relapse when withdrawing those antifungal agents.

Evidence for Nonlinear Gluon Effects in QCD and Their Mass Number Dependence at STAR

The STAR Collaboration reports measurements of back-to-back azimuthal correlations of di-π^{0}s produced at forward pseudorapidities (2.6<η<4.0) in p+p, p+Al, and p+Au collisions at a center-of-mass energy of 200 GeV. We observe a clear suppression of the correlated yields of back-to-back π^{0} pairs in p+Al and p+Au collisions compared to the p+p data. The observed suppression of back-to-back pairs as a function of transverse momentum suggests nonlinear gluon dynamics arising at high parton densities. The larger suppression found in p+Au relative to p+Al collisions exhibits a dependence of the saturation scale Q_{s}^{2} on the mass number A. A linear scaling of the suppression with A^{1/3} is observed with a slope of -0.09±0.01.

[Prevalence and risk factors of Giardia lamblia infections among colorectal cancer patients in Henan Province]

OBJECTIVE

To investigate the epidemiological characteristics and identify the risk factors of Giardia lamblia infections among patients with colorectal cancer in Henan Province.

METHODS

A cross-sectional study was performed for questionnaire surveys among colorectal cancer patients in Henan Cancer Hospital during the period from March to July, 2021. Patients' stool samples were collected, and the triosephosphate isomerase (tpi) gene of G. lamblia was amplified in stool samples using nested PCR assay to characterize the parasite genotype. Univariate analysis and multivariate logistic regression analyses were employed to identify the risk factors of G. lamblia infections among colorectal cancer patients.

RESULTS

A total of 307 colorectal cancer patients were investigated, including 176 males (57.3%) and 131 females (42.7%). PCR assay detected 8.1% [95% confidential interval (CI): (0.056, 0.117)] prevalence of G. lamblia infections among the study subjects, and there was no significant difference in the prevalence between men [9.1%, 95% CI: (0.057, 0.143)] and women [6.9%, 95% CI: (0.037, 0.125)] (χ² = 0.495, P = 0.482). In addition, there was no age-specific prevalence of G. lamblia infections among the participants (χ² = 1.534, P = 0.675). Multivariate logistic regression analysis identified use of septic tanks [odds ratio (OR) = 3.336, 95% CI: (1.201, 9.267)], daily use of well water [OR = 3.042, 95% CI: (1.093, 8.465)] and raising livestock [OR = 3.740, 95% CI: (1.154, 12.121)] as risk factors of G. lamblia infections among colorectal cancer patients, and the prevalence of abdominal pain was significantly greater in colorectal cancer patients with G. lamblia infections than in those without infections (P = 0.017). Among the 25 patients with G. lamblia infections, assemblage A was characterized in 24 (96.0%) cases and assemblage B in one case (4.0%).

CONCLUSIONS

The prevalence of G. lamblia is high among colorectal cancer patients in Henan Province, and assemblage A is the dominant genotype of G. lamblia. Use of septic tanks, daily use of well water and raising livestock are risk factors of G. lamblia infections among patients with colorectal cancer.

Investigation on the incidence and risk factors of lung cancer among Chinese hospital employees

Objective

In recent years, the lung cancer incidence has grown and the population is younger. We intend to find out the true detection rate of pulmonary nodules and the incidence of lung cancer in the population and search for the risk factors.

Method

Hospital employees ≥40 years old who underwent low‐dose computed tomography (CT) lung cancer screening from January 2019 to March 2022 were selected to record CT‐imaging characteristics, pathology, staging, and questionnaires to investigate past history, smoking history, diet, mental health, etc. PM2.5 and radiation intake in radiation‐related occupation received monitoring in hospital.

Result

The detection rate of suspicious pulmonary nodules was 9.1% (233/2552), and the incidence rate of lung cancer (including adenocarcinoma in situ) was 4.0% (103/2552). Morbidity among doctors, nurses, technicians, administers, and logistics was no difference (p = 0.184), but higher in women than in men (4.7% vs 2.4% p = 0.002). The invasiveness increased with age and CT density of nodules (p = 0.018). The relationship between lung cancer morbidity and PM2.5 was not clear (p = 0.543); and no lung cancer has been found in employees related ionizing radiation.

Conclusion

The high screening rate has brought about a high incidence of lung cancer. At present, the risk factor analysis of lung cancer based on small samples cannot find the direct cause. Most of the ground glass opacity (GGO)s detected by LDCT screening are indolent, but there are also rapidly progressive lung cancer. A predictive model to identify active and indolent GGO is necessary.

[Effect of behavioral intervention based on social media to promote HIV/syphilis testing in young men who have sex with men]

Objective: To evaluate the effect of social media based behavioral intervention on promoting joint testing of HIV and syphilis in young men who have sex with men (MSM). Methods: After the recruitment, the participants who met the inclusion criteria were randomly divided (1∶1) into two groups, i.e. social media intervention group and control group. The control group was given routine voluntary counseling and testing (VCT) services. The intervention group was also given VCT services, besides; the comprehensive strategies through social media, including regular health education message and testing information sending, were given to them to strengthen the behavioral intervention. Follow up was conducted for the participants for 12 months after the intervention. The number and the proportion of young MSM receiving HIV and syphilis testing, and the reported proportion of the young MSM with sexually transmitted diseases (STD) symptoms between the intervention group and the control group were compared to evaluate the effect of the intervention. Results: A total of 315 young MSM were recruited (158 in the intervention group and 157 in the control group), in whom 248 young MSM completed the follow up. The follow-up rate was 78.7%. There was no significant difference in baseline characteristics between the intervention group and the control group (all P>0.05). The proportion of young MSM receiving more than one joint testing in the intervention group was slightly higher than that in the control group (53.2% vs. 48.4%, rate difference (RD): 4.8%, 95%CI: -7.5%-17.0%, P=0.448) without significant difference. However, in the young MSM who used condoms in the last anal sex, the proportion of those receiving more than one joint testing in the intervention group was higher than that in the control group (63.8% vs. 46.1%, RD: 17.7%, 95%CI: 1.5%-32.6%, P=0.035). In addition, the reported proportion of young MSM with STD symptoms in the intervention group was significantly lower than that in the control group (6.3% vs. 18.0%,RD: -11.7%, 95%CI: -20.6%- -3.0%, P=0.005). Conclusion: Compared with routine VCT, social media based behavioral intervention might promote joint HIV and syphilis testing in the young MSM who used condom in the study. It could significantly reduce the reporting proportion of STD symptoms, suggesting that this method can promote the AIDS and STD prevention related behaviors in young MSM.

Measurements of Proton High-Order Cumulants in sqrt[s_{NN}]=3 GeV Au+Au Collisions and Implications for the QCD Critical Point

We report cumulants of the proton multiplicity distribution from dedicated fixed-target Au+Au collisions at sqrt[s_{NN}]=3.0  GeV, measured by the STAR experiment in the kinematic acceptance of rapidity (y) and transverse momentum (p_{T}) within -0.5<y<0 and 0.4<p_{T}<2.0  GeV/c. In the most central 0%-5% collisions, a proton cumulant ratio is measured to be C_{4}/C_{2}=-0.85±0.09 (stat)±0.82 (syst), which is 2σ below the Poisson baseline with respect to both the statistical and systematic uncertainties. The hadronic transport UrQMD model reproduces our C_{4}/C_{2} in the measured acceptance. Compared to higher energy results and the transport model calculations, the suppression in C_{4}/C_{2} is consistent with fluctuations driven by baryon number conservation and indicates an energy regime dominated by hadronic interactions. These data imply that the QCD critical region, if created in heavy-ion collisions, could only exist at energies higher than 3 GeV.

Measurements of _{Λ}^{3}H and _{Λ}^{4}H Lifetimes and Yields in Au+Au Collisions in the High Baryon Density Region

We report precision measurements of hypernuclei _{Λ}^{3}H and _{Λ}^{4}H lifetimes obtained from Au+Au collisions at sqrt[s_{NN}]=3.0  GeV and 7.2 GeV collected by the STAR experiment at the Relativistic Heavy Ion Collider, and the first measurement of _{Λ}^{3}H and _{Λ}^{4}H midrapidity yields in Au+Au collisions at sqrt[s_{NN}]=3.0  GeV. _{Λ}^{3}H and _{Λ}^{4}H, being the two simplest bound states composed of hyperons and nucleons, are cornerstones in the field of hypernuclear physics. Their lifetimes are measured to be 221±15(stat)±19(syst)  ps for _{Λ}^{3}H and 218±6(stat)±13(syst)  ps for _{Λ}^{4}H. The p_{T}-integrated yields of _{Λ}^{3}H and _{Λ}^{4}H are presented in different centrality and rapidity intervals. It is observed that the shape of the rapidity distribution of _{Λ}^{4}H is different for 0%-10% and 10%-50% centrality collisions. Thermal model calculations, using the canonical ensemble for strangeness, describes the _{Λ}^{3}H yield well, while underestimating the _{Λ}^{4}H yield. Transport models, combining baryonic mean-field and coalescence (jam) or utilizing dynamical cluster formation via baryonic interactions (phqmd) for light nuclei and hypernuclei production, approximately describe the measured _{Λ}^{3}H and _{Λ}^{4}H yields. Our measurements provide means to precisely assess our understanding of the fundamental baryonic interactions with strange quarks, which can impact our understanding of more complicated systems involving hyperons, such as the interior of neutron stars or exotic hypernuclei.

Probing the Gluonic Structure of the Deuteron with J/ψ Photoproduction in d+Au Ultraperipheral Collisions

Understanding gluon density distributions and how they are modified in nuclei are among the most important goals in nuclear physics. In recent years, diffractive vector meson production measured in ultraperipheral collisions (UPCs) at heavy-ion colliders has provided a new tool for probing the gluon density. In this Letter, we report the first measurement of J/ψ photoproduction off the deuteron in UPCs at the center-of-mass energy sqrt[s_{NN}]=200  GeV in d+Au collisions. The differential cross section as a function of momentum transfer -t is measured. In addition, data with a neutron tagged in the deuteron-going zero-degree calorimeter is investigated for the first time, which is found to be consistent with the expectation of incoherent diffractive scattering at low momentum transfer. Theoretical predictions based on the color glass condensate saturation model and the leading twist approximation nuclear shadowing model are compared with the data quantitatively. A better agreement with the saturation model has been observed. With the current measurement, the results are found to be directly sensitive to the gluon density distribution of the deuteron and the deuteron breakup process, which provides insights into the nuclear gluonic structure.

Search for the Chiral Magnetic Effect via Charge-Dependent Azimuthal Correlations Relative to Spectator and Participant Planes in Au+Au Collisions at sqrt[s_{NN}]=200 GeV

The chiral magnetic effect (CME) refers to charge separation along a strong magnetic field due to imbalanced chirality of quarks in local parity and charge-parity violating domains in quantum chromodynamics. The experimental measurement of the charge separation is made difficult by the presence of a major background from elliptic azimuthal anisotropy. This background and the CME signal have different sensitivities to the spectator and participant planes, and could thus be determined by measurements with respect to these planes. We report such measurements in Au+Au collisions at a nucleon-nucleon center-of-mass energy of 200 GeV at the Relativistic Heavy-Ion Collider. It is found that the charge separation, with the flow background removed, is consistent with zero in peripheral (large impact parameter) collisions. Some indication of finite CME signals is seen in midcentral (intermediate impact parameter) collisions. Significant residual background effects may, however, still be present.

Oncologic Benefit of Adjuvant Therapy in Lateral Pelvic Lymph Node Metastasis following Neoadjuvant Chemoradiotherapy and Lateral Pelvic Lymph Node Dissection

Background: It remains controversial whether the addition of adjuvant chemotherapy (ACT) to total mesorectal excision (TME) plus lateral pelvic lymph node dissection (LLND) can provide a survival benefit after neoadjuvant chemoradiotherapy (nCRT) in patients with clinically suspected lateral pelvic lymph node metastasis (LPNM). We aim to investigate the effectiveness of ACT after nCRT with TME plus LLND for patients with clinically suspected LPNM.

Methods: From January 2015 to December 2021, 138 patients with clinically suspected LPNM who were treated with nCRT followed by TME plus LLND at three institutions were enrolled in this study. The patients were categorized into the ACT group (n = 95) and the non‐ACT group (n = 43).

Results: The mean follow-up period was 37 months. The 3-year disease-free survival (DFS) rate for the entire cohort was 74.8%. Ninety-five patients (68.8%) received ACT, without any oncologic benefit (3-year DFS rates for the ACT and non-ACT groups were 67.0% and 80.5%, respectively, P = 0.130). Additionally, multivariate analysis showed that lymphatic invasion (hazard ratio [HR]: 6.26, P = 0.005) was an independent risk factor for DFS. Subgroup analyses revealed that for patients ≥ 64 years and those with ypStage 0, the distribution of 95% confidence interval (CI) values tended to focus on the non-ACT strategy.

Conclusion: The efficacy of the addition of ACT to TME plus LLND after nCRT in LARC patients with clinically suspected LPNM was not confirmed in this study. Moreover, patients with age ≥ 64 years and those with ypStage 0 may not receive benefit from ACT after nCRT followed by TME plus LLND.

Measurement of the Sixth-Order Cumulant of Net-Proton Multiplicity Distributions in Au+Au Collisions at sqrt[s_{NN}]=27, 54.4, and 200 GeV at RHIC

According to first-principle lattice QCD calculations, the transition from quark-gluon plasma to hadronic matter is a smooth crossover in the region μ_{B}≤T_{c}. In this range the ratio, C_{6}/C_{2}, of net-baryon distributions are predicted to be negative. In this Letter, we report the first measurement of the midrapidity net-proton C_{6}/C_{2} from 27, 54.4, and 200 GeV Au+Au collisions at the Relativistic Heavy Ion Collider (RHIC). The dependence on collision centrality and kinematic acceptance in (p_{T}, y) are analyzed. While for 27 and 54.4 GeV collisions the C_{6}/C_{2} values are close to zero within uncertainties, it is observed that for 200 GeV collisions, the C_{6}/C_{2} ratio becomes progressively negative from peripheral to central collisions. Transport model calculations without critical dynamics predict mostly positive values except for the most central collisions within uncertainties. These observations seem to favor a smooth crossover in the high-energy nuclear collisions at top RHIC energy.

[Prospective clinical study on the influence of implant crown and bridge prostheses characteristics on peri-implant disease]

Objective: To investigate the influence of different characteristics of implant-supported fixed dental prostheses on the incidence of peri-implant disease. Methods: Prospective cohort was established for patients who received implant-supported fixed dental prostheses at the Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University between June 2014 and September 2015. Several patient-related factors, implant prostheses factors, and oral hygiene maintenance factors were collected. The Log-rank test was used to compare the peri-implant disease rates of various factors, and the Cox proportional hazards model was used to conduct multivariate study on single factor significant factors to analyze the impact on the incidence of peri-implant disease. Results: A total of 214 subjects and 351 implants were included in the cohort, the follow-up period was (11.0±3.5) months. Finally, 43.0% (92/214) of patients and 37.3% (131/351) of implants developed peri-implant diseases. The incidence of peri-implant mucositis and peri-implantitis was 41.1% (88/214) and 4.2% (9/214) at the subject level,and 34.2% (120/351) and 3.1% (11/351) at the implant level. Among the factors associated with the implant prosthesis, single factor Log-rank analysis showed that prostheses retention methods, proximal contact of the prostheses, occlusion situation were statistical significance (P<0.05). Multivariate analysis using Cox proportional hazards model showed that screw retention (hazard ratio=2.38, 95%CI: 1.42-3.99), proximal contact loss of the prostheses (hazard ratio=2.36, 95%CI: 1.31-4.27) were independent risk factors for peri-implant disease (P<0.05). Conclusions: Factors such as prostheses retention mode and proximal contact characteristics have important influence on the health status of the implant.

DFT study on the adsorption of 5-fluorouracil on B40, B39M, and M@B40 (M = Mg, Al, Si, Mn, Cu, Zn)

Based on density functional theory, the adsorption behavior of 5-fluorouracil (5-Fu) on B₄₀ and its derivatives has been explored. It was observed that 5-Fu prefers to combine with the corner boron atom of the B₄₀ cage via one of its oxygen atoms, forming a strong polar covalent B–O bond. The adsorption energy of 5-Fu on B₄₀ was calculated to be −11.15 kcal mol⁻¹, and thus, it can be duly released from B₄₀ by protonation in the slightly acidic environment of tumor tissue, which makes for reducing the toxic and side effects of this drug. Additionally, the substituent and embedding effect of Mg, Al, Si, Mn, Cu, and Zn atoms on the drug delivery performance of B₄₀ have been also considered. We hope this work could offer some implications for the potential application of boron-based nanomaterials, such as B₄₀ in drug delivery.

The adsorption of 5-fluorouracil on B₄₀ and its derivatives has been theoretically studied to provide some implications for the potential application of B₄₀ in drug delivery.

BRCA1 Expression and Outcome in Patients With EGFR-Mutant NSCLC Treated With Gefitinib Alone or in Combination With Olaparib

Introduction

DNA repair capacity, as exemplified by BRCA1 gene expression, is related with outcome to EGFR tyrosine kinase inhibitors in patients with EGFR-mutant NSCLC. Olaparib, a PARP inhibitor, reduces BRCA1 expression. Olaparib was tested in combination with gefitinib versus gefitinib single agent, as a first-line therapy for patients with EGFR-mutant NSCLC in the GOAL study (trial registration: NCT01513174). Here, we report the results of the biomarker-related prespecified secondary objectives of the GOAL study.

Methods

We evaluated the impact of BRCA1 mRNA expression in 91 patients with EGFR-mutant NSCLC. Of those 91 patients, 51 were randomized to treatment with gefitinib and 40 were randomized to treatment with gefitinib plus olaparib. We explored in vitro whether BRCA1 mRNA levels are related with outcome to gefitinib plus olaparib. The expression levels of 53BP1, CtIP, and AXL were also explored and correlated with the treatment outcome.

Results

Overall, as what happened in the GOAL study, no statistically significant difference was observed in median progression-free survival (PFS) between the two treatment arms, for the 91 patients of the present study (p = 0.2419). For patients with high BRCA1 mRNA expression (BRCA1-high group), median PFS was 12.9 months in the gefitinib plus olaparib arm, compared with 9.2 months in the gefitinib arm (p = 0.0449). In the gefitinib arm, median PFS was 9.1 months for the BRCA1-high group and 10.2 months for the BRCA1-low group (p = 0.0193). We observed a more pronounced synergism of gefitinib plus olaparib in cells with higher BRCA1 compared with those with low BRCA1 mRNA expression.

Conclusions

High BRCA1 mRNA expression identified patients with NSCLC who benefited from gefitinib plus olaparib in the GOAL phase 2 clinical trial.

A unique photosystem I reaction center from a chlorophyll d-containing cyanobacterium Acaryochloris marina

Photosystem I (PSI) is a large protein supercomplex that catalyzes the light-dependent oxidation of plastocyanin (or cytochrome c₆ ) and the reduction of ferredoxin. This catalytic reaction is realized by a transmembrane electron transfer chain consisting of primary electron donor (a special chlorophyll (Chl) pair) and electron acceptors A₀ , A₁ , and three Fe₄ S₄ clusters, F_X , F_A , and F_B . Here we report the PSI structure from a Chl d-dominated cyanobacterium Acaryochloris marina at 3.3 Å resolution obtained by single-particle cryo-electron microscopy. The A. marina PSI exists as a trimer with three identical monomers. Surprisingly, the structure reveals a unique composition of electron transfer chain in which the primary electron acceptor A₀ is composed of two pheophytin a rather than Chl a found in any other well-known PSI structures. A novel subunit Psa27 is observed in the A. marina PSI structure. In addition, 77 Chls, 13 α-carotenes, two phylloquinones, three Fe-S clusters, two phosphatidyl glycerols, and one monogalactosyl-diglyceride were identified in each PSI monomer. Our results provide a structural basis for deciphering the mechanism of photosynthesis in a PSI complex with Chl d as the dominating pigments and absorbing far-red light.

Designing an alkali-metal-like superatom Ca3B for ambient nitrogen reduction to ammonia

Converting earth-abundant nitrogen (N₂) gas into ammonia (NH₃) under mild conditions is one of the most important issues and a long-standing challenge in chemistry. Herein, a new superatom Ca₃B was theoretically designed and characterized to reveal its catalytic performance in converting N₂ into NH₃ by means of density functional theory (DFT) computations. The alkali-metal-like identity of this cluster is verified by its lower vertical ionization energy (VIE, 4.29 eV) than that of potassium (4.34 eV), while its high stability was guaranteed by the large HOMO-LUMO gap and binding energy per atom (E_b). More importantly, this well-designed superatom possesses unique geometric and electronic features, which can fully activate N₂via a "double-electron transfer" mechanism, and then convert the activated N₂ into NH₃ through a distal reaction pathway with a small energy barrier of 0.71 eV. It is optimistically hoped that this work could intrigue more endeavors to design specific superatoms as excellent catalysts for the chemical adsorption and reduction of N₂ to NH₃.

[Chlamydia psittaci pneumonia complicated with rhabdomyolysis: a case report and literature review]

Objective: To analyze the clinical characteristics and the diagnosis and treatment of Chlamydia psittaci pneumonia complicated with rhabdomyolysis. Methods: We reported a case of Chlamydia psittaci pneumonia complicated with rhabdomyolysis. We did a literature review on the published reports between January 1978 and May 2020 by searching with the key words of "psittacosis" or "Chlamydia psittaci" and "rhabdomyolysis" in the PubMed database (time frame: January 1, 1967 to May 30, 2020). Results: Our patient was a 64-year-old male presenting with high-grade fever, fatigue, myalgia and dyspnea. A computed tomographic scan of the chest revealed bilateral pneumonia, which was further complicated with rhabdomyolysis during disease progression. This prompted the metagenomic next-generation sequencing, revealing the sequences of Chlamydia psittaci in both the bronchoalveolar lavage fluid and blood. Of the 11 cases in the 3 literature reports that we retrieved, 5 had concomitant rhabdomyolysis (two of which did not have complete clinical information), and the other 6 cases had myositis complicated with an elevated level of creatine phosphokinase. This yielded 3 cases with complete clinical information for our analysis. We had further incorporated their information with the single case managed within our study site. Two were males and the other 2 were females. The patients were aged 66, 46, 44 and 64 years, respectively. All cases had fever and 3 had a contact history with live poultry. Two cases had myalgia and progressed rapidly into having respiratory failure, and the other 2 cases did not develop myalgia and improved significantly after a timely treatment. All 4 cases were cured and discharged after treatment with appropriate antibiotics. No adverse outcomes were observed. Conclusions: The prognosis of Chlamydia psittaci pneumonia complicated with rhabdomyolysis was poor in case of a delayed treatment. Early diagnosis would help reduce the mortality.

Observation of D_{s}^{±}/D^{0} Enhancement in Au+Au Collisions at sqrt[s_{NN}]=200 GeV

We report on the first measurement of charm-strange meson D_{s}^{±} production at midrapidity in Au+Au collisions at sqrt[s_{NN}]=200  GeV from the STAR experiment. The yield ratio between strange (D_{s}^{±}) and nonstrange (D^{0}) open-charm mesons is presented and compared to model calculations. A significant enhancement, relative to a pythia simulation of p+p collisions, is observed in the D_{s}^{±}/D^{0} yield ratio in Au+Au collisions over a large range of collision centralities. Model calculations incorporating abundant strange-quark production in the quark-gluon plasma and coalescence hadronization qualitatively reproduce the data. The transverse-momentum integrated yield ratio of D_{s}^{±}/D^{0} at midrapidity is consistent with a prediction from a statistical hadronization model with the parameters constrained by the yields of light and strange hadrons measured at the same collision energy. These results suggest that the coalescence of charm quarks with strange quarks in the quark-gluon plasma plays an important role in D_{s}^{±}-meson production in heavy-ion collisions.

Measurement of e^{+}e^{-} Momentum and Angular Distributions from Linearly Polarized Photon Collisions

The Breit-Wheeler process which produces matter and antimatter from photon collisions is experimentally investigated through the observation of 6085 exclusive electron-positron pairs in ultraperipheral Au+Au collisions at sqrt[s_{NN}]=200  GeV. The measurements reveal a large fourth-order angular modulation of cos4Δϕ=(16.8±2.5)% and smooth invariant mass distribution absent of vector mesons (ϕ, ω, and ρ) at the experimental limit of ≤0.2% of the observed yields. The differential cross section as a function of e^{+}e^{-} pair transverse momentum P_{⊥} peaks at low value with sqrt[⟨P_{⊥}^{2}⟩]=38.1±0.9  MeV and displays a significant centrality dependence. These features are consistent with QED calculations for the collision of linearly polarized photons quantized from the extremely strong electromagnetic fields generated by the highly charged Au nuclei at ultrarelativistic speed. The experimental results have implications for vacuum birefringence and for mapping the magnetic field which is important for emergent QCD phenomena.

Global Polarization of Ξ and Ω Hyperons in Au+Au Collisions at sqrt[s_{NN}]=200 GeV

Global polarization of Ξ and Ω hyperons has been measured for the first time in Au+Au collisions at sqrt[s_{NN}]=200  GeV. The measurements of the Ξ^{-} and Ξ[over ¯]^{+} hyperon polarization have been performed by two independent methods, via analysis of the angular distribution of the daughter particles in the parity violating weak decay Ξ→Λ+π, as well as by measuring the polarization of the daughter Λ hyperon, polarized via polarization transfer from its parent. The polarization, obtained by combining the results from the two methods and averaged over Ξ^{-} and Ξ[over ¯]^{+}, is measured to be ⟨P_{Ξ}⟩=0.47±0.10(stat)±0.23(syst)% for the collision centrality 20%-80%. The ⟨P_{Ξ}⟩ is found to be slightly larger than the inclusive Λ polarization and in reasonable agreement with a multiphase transport model. The ⟨P_{Ξ}⟩ is found to follow the centrality dependence of the vorticity predicted in the model, increasing toward more peripheral collisions. The global polarization of Ω, ⟨P_{Ω}⟩=1.11±0.87(stat)±1.97(syst)% was obtained by measuring the polarization of daughter Λ in the decay Ω→Λ+K, assuming the polarization transfer factor C_{ΩΛ}=1.