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.

[Clinical features of 141 fatal cases of coronavirus disease in Jinyintan Hospital in Wuhan, China]

Objective: To describe the epidemiological characteristics and clinical features of patients with fatal coronavirus disease (COVID-19), in order to provide evidence for clinical diagnosis and treatment. Methods: In this retrospective study, we analyzed data on 141 fatal cases of confirmed COVID-19 that occurred among patients in Jinyintan Hospital in Wuhan, China, from January 20 to March 6, 2020. We analyzed their epidemiological characteristics, clinical and radiological features, laboratory results, and treatment. Results: Of the 141 patients (49 females, 92 males), the median age was 77 years (range: 24-92 years). The most likely source of exposure included the Huanan seafood market (n=3, 2%), family members (n=6, 4%), and hospital-acquired infection (n=8, 6%). The remaining 116 patients (72%) had no known source of exposure. Of the patients, 101 (72%) had chronic diseases. The most common comorbidities were hypertension, diabetes and coronary heart disease. The most common clinical manifestations were fever (n=121, 85%), dry cough (n=77, 54%), shortness of breath (n=23, 16%), and chest pain (n=15, 10%). Less common clinical manifestations included fatigue (n=7, 4%), headache (n=3, 2%), disorders of consciousness (n=2, 1%), diarrhea (n=2, 1%) and lumbago (n=1, 0.7%). In terms of laboratory tests, the absolute value of lymphocytes in most patients was reduced (n=132, 94%), but C-reactive protein (n=141, 100%), procalcitonin(n=121, 89%), serum amyloid (n=140, 99%) were significantly increased. The most common findings on imaging of the lungs were bilateral multiple mottling and ground-glass opacity (n=101, 72%), mainly in the lower lobes (n=15, 10%), with lesions being more common on the right. Other imaging findings included diffuse consolidation (n=4, 3%), ground-glass opacity and consolidation (n=20, 14%), and pneumothorax (n=1, 0.7%). All patients were treated with antibiotics and antiviral drugs. Other treatments included immunoglobulin (n=49, 35%), corticosteroids (n=45, 32%), continuous renal replacement therapy (n=24, 17%), and extracorporeal membrane oxygenation (n=12, 9%). All patients were treated with oxygen therapy. The mode of administration included invasive mechanical ventilation (n=61, 43%), noninvasive mechanical ventilation (n=65, 46%), and nasal catheter oxygen inhalation (n=15, 11%). The direct causes of death were acute respiratory distress syndrome (n=90, 64%), multiple organ failure (n=24, 17%), sudden cardiac arrest (n=11, 8%), viral myocarditis (n=8, 5%), acute myocardial infarction (n=4, 3%), cerebrovascular accident (n=3, 2%), and acute gastrointestinal bleeding (n=1, 0.7%). Conclusions: Risk factors for death due to COVID-19 included older age, male sex, and the presence of comorbidities. The most common direct causes of death were acute respiratory distress syndrome, multiple organ failure, sudden cardiac arrest, and viral myocarditis.

Gas explosion-induced acute blast lung injury assessment and biomarker identification by a LC-MS-based serum metabolomics analysis

The objective of this study was to evaluate the histopathological effect of gas explosion on rats, and to explore the metabolic alterations associated with gas explosion-induced acute blast lung injury (ABLI) in real roadway environment using metabolomics analyses. All rats were exposed to the gas explosion source at different distance points (160 m and 240 m) except the control group. Respiratory function indexes were monitored and lung tissue analysis was performed to correlate histopathological effect to serum metabolomics. Their sera samples were collected to measure the metabolic alterations by ultra-performance liquid chromatography-mass spectrometry (UPLC-MS). HE staining in lung showed that the gas explosion caused obvious inflammatory pulmonary injury, which was consistent with respiratory function monitoring results and the serum metabolomics analysis results. The metabolomics identified 9 significantly metabolites different between the control- and ABLI rats. 2-aminoadipic acid, L-methionine, L-alanine, L-lysine, L-threonine, cholic acid and L-histidine were significantly increased in the exposed groups. Citric acid and aconitic acid were significantly decreased after exposure. Pathway analyses identified 8 perturbed metabolic pathways, which provided novel potential mechanisms for the gas explosion-induced ABLI. Therefore, metabolomics analysis identified both known and unknown alterations in circulating biomarkers, adding an integral mechanistic insight into the gas explosion-induced ABLI in real roadway environment.

Observation of a Near-Threshold Structure in the K^{+} Recoil-Mass Spectra in e^{+}e^{-}→K^{+}(D_{s}^{-}D^{*0}+D_{s}^{*-}D^{0})

We report a study of the processes of e^{+}e^{-}→K^{+}D_{s}^{-}D^{*0} and K^{+}D_{s}^{*-}D^{0} based on e^{+}e^{-} annihilation samples collected with the BESIII detector operating at BEPCII at five center-of-mass energies ranging from 4.628 to 4.698 GeV with a total integrated luminosity of 3.7  fb^{-1}. An excess of events over the known contributions of the conventional charmed mesons is observed near the D_{s}^{-}D^{*0} and D_{s}^{*-}D^{0} mass thresholds in the K^{+} recoil-mass spectrum for events collected at sqrt[s]=4.681  GeV. The structure matches a mass-dependent-width Breit-Wigner line shape, whose pole mass and width are determined as (3982.5_{-2.6}^{+1.8}±2.1)  MeV/c^{2} and (12.8_{-4.4}^{+5.3}±3.0)  MeV, respectively. The first uncertainties are statistical and the second are systematic. The significance of the resonance hypothesis is estimated to be 5.3  σ over the contributions only from the conventional charmed mesons. This is the first candidate for a charged hidden-charm tetraquark with strangeness, decaying into D_{s}^{-}D^{*0} and D_{s}^{*-}D^{0}. However, the properties of the excess need further exploration with more statistics.

Nonmonotonic Energy Dependence of Net-Proton Number Fluctuations

Nonmonotonic variation with collision energy (sqrt[s_{NN}]) of the moments of the net-baryon number distribution in heavy-ion collisions, related to the correlation length and the susceptibilities of the system, is suggested as a signature for the quantum chromodynamics critical point. We report the first evidence of a nonmonotonic variation in the kurtosis times variance of the net-proton number (proxy for net-baryon number) distribution as a function of sqrt[s_{NN}] with 3.1  σ significance for head-on (central) gold-on-gold (Au+Au) collisions measured solenoidal tracker at Relativistic Heavy Ion Collider. Data in noncentral Au+Au collisions and models of heavy-ion collisions without a critical point show a monotonic variation as a function of sqrt[s_{NN}].

Strain wave pathway to semiconductor-to-metal transition revealed by time-resolved X-ray powder diffraction

One of the main challenges in ultrafast material science is to trigger phase transitions with short pulses of light. Here we show how strain waves, launched by electronic and structural precursor phenomena, determine a coherent macroscopic transformation pathway for the semiconducting-to-metal transition in bistable Ti₃O₅ nanocrystals. Employing femtosecond powder X-ray diffraction, we measure the lattice deformation in the phase transition as a function of time. We monitor the early intra-cell distortion around the light absorbing metal dimer and the long range deformations governed by acoustic waves propagating from the laser-exposed Ti₃O₅ surface. We developed a simplified elastic model demonstrating that picosecond switching in nanocrystals happens concomitantly with the propagating acoustic wavefront, several decades faster than thermal processes governed by heat diffusion.

Liquid biopsy by combining 5-hydroxymethylcytosine signatures of plasma cell-free DNA and protein biomarkers for diagnosis and prognosis of hepatocellular carcinoma

BACKGROUND

Liquid biopsy based on 5-hydroxymethylcytosine (5hmC) signatures of plasma cell-free DNA (cfDNA) originating from tumor cells provides a novel approach for early diagnosis in hepatocellular carcinoma (HCC). Here, we sought to develop a reliable model using cfDNA 5hmC signatures and protein biomarkers for diagnosis and prognosis of HCC.

PATIENTS AND METHODS

We carried out genome-wide 5hmC sequencing of cfDNA samples collected from 165 healthy volunteers, 62 liver cirrhosis (LC) patients and 135 HCC patients. A sensitive 5hmC diagnostic model was developed based on 5hmC signatures selected by sparse Partial Least Squares Discriminant Analysis and cross-validation to define the weighted diagnostic score (wd-score). Then, we combined protein biomarkers with the wd-score to build a more robust score (HCC score) by logistic regression.

RESULTS

The distribution pattern of differential 5hmC regions could clearly distinguish HCC patients, LC patients and healthy volunteers. The wd-score based on 64 5hmC signatures in cfDNA achieves 93.24% of area under the curve (AUC) to distinguish HCC patients from non-HCC patients, and the HCC score by combing protein biomarkers achieves 92.75% of AUC to distinguish HCC patients from LC patients. Meanwhile, the HCC score showed high capacity for screening high recurrence risk patients after receiving surgical resection, and appeared to be an independent indicator for both relapse-free survival (P = 0.00865) and overall survival (P = 0.000739). Furthermore, the values of the HCC score in patients' longitudinal plasma samples were positively associated with tumor burden dynamics during follow-up.

CONCLUSION

We have developed and validated a novel non-invasive liquid biopsy strategy for HCC diagnosis, prognosis and surveillance during HCC progression.

Opsin 5 is a key regulator of ultraviolet radiation-induced melanogenesis in human epidermal melanocytes

Background

Human skin, which is constantly exposed to solar ultraviolet radiation (UVR), has a unique ability to respond by increasing its pigmentation in a protective process driven by melanogenesis in human epidermal melanocytes (HEMs). However, the molecular mechanisms used by HEMs to detect and respond to UVR remain unclear.

Objectives

To investigate the function and potential mechanism of opsin 5 (OPN5), a photoreceptor responsive to UVR wavelengths, in melanogenesis in HEMs.

Methods

Melanin content in HEMs was determined using the NaOH method, and activity of tyrosinase (TYR) (a key enzyme in melanin synthesis) was determined by the l‐DOPA method. OPN5 expression in UVR‐treated vs. untreated HEMs and explant tissues was detected by reverse‐transcription quantitative polymerase chain reaction (RT‐qPCR), Western blotting and immunofluorescence. Short interfering RNA‐mediated OPN5 knockdown and a lentivirus OPN5 overexpression model were used to examine their respective effects on TYR, tyrosinase‐related protein 1 (TRP1), TRP2 and microphthalmia‐associated transcription factor (MITF) expression, under UVR. Changes in expression of TYR, TRP1 and TRP2 caused by changes in OPN5 expression level were detected by RT‐qPCR and Western blot. Furthermore, changes in signalling pathway proteins were assayed.

Results

We found that OPN5 is the key sensor in HEMs responsible for UVR‐induced melanogenesis. OPN5‐induced melanogenesis required Ca²⁺‐dependent G protein‐coupled receptor‐ and protein kinase C signal transduction, thus contributing to the UVR‐induced MITF response to mediate downstream cellular effects, and providing evidence of OPN5 function in mammalian phototransduction. Remarkably, OPN5 activation was necessary for UVR‐induced increase in cellular melanin and has an inherent function in melanocyte melanogenesis.

Conclusions

Our results provide insight into the molecular mechanisms of UVR sensing and phototransduction in melanocytes, and may reveal molecular targets for preventing pigmentation or pigment diseases.

What is already known about this topic?

Ultraviolet radiation (UVR) induces a protective response to DNA damage mediated by melanin synthesis in human epidermal melanocytes (HEMs).

Tyrosinase (TYR), with tyrosinase‐related proteins (TRP1, TRP2), are the key enzymes for melanin synthesis.

Microphthalmia‐associated transcription factor regulates key genes for melanocyte development and differentiation, and can stimulate melanogenesis by activating transcription of TYR and other pigmentation genes, including TRP1.

Opsin 5 (OPN5) is known to function as a photoreceptor responsive to wavelengths in the near UV spectrum.

What does this study add?

UVR induces melanogenesis in HEMs via OPN5.

OPN5 regulates expression of TYR, TRP1 and TRP2 through the calcium‐dependent G protein‐coupled and protein kinase C signalling pathways.

OPN5 has an inherent role in HEMs in mediating melanogenesis.

What is the translational message?

OPN5 was discovered as a key sensor for UVR‐induced melanogenesis in human skin melanocytes.

It could be a target for early treatment of pigmentation or pigment diseases, to provide a more personalized and economically feasible method.

Linked Comment: L.V.M. de Assis and A.M. de Lauro Castrucci. Br J Dermatol 2021; 185:249–250.

Plain language summary available online

[Genotype distribution and behavioral risk factor analysis of human papillomavirus infection among Kazak women in Xinjiang Uygur Autonomous Region]

Objective: To investigate the prevalence and genotype distribution of high-risk human papillomavirus (HR-HPV) and the correlation between cervical lesions and analyze the risk factors for HR-HPV infection. Methods: In June 2018, a population-based study for cervical cancer screening in Tuoli county of Xinjiang Uygur Autonomous Region was conducted. A total of 2 000 Kazak women aged 25-64 years were included in the study. Three cervical exfoliated cells samples were collected from them for careHPV, PCR HPV, p16(INK4a), and liquid-based cytology (LBC) tests. Women with any positive test were referred for colposcopy with biopsies taken at abnormal sites. Histo-pathological diagnoses were used as the gold standard. Results: The overall prevalence of HPV was 14.55%, among which the infection rate of HR-HPV was 12.90%, which was even higher in the 50-54 years age group. The most prevalent genotypes of HR-HPV were HPV16 (2.80%), HPV51(2.35%), HPV52 (1.70%), HPV56 (1.50%), and HPV39 (1.20%). The most common HPV infection was a single infection (71.48%). In the age group of 50-54 years, the multiple infection rates were higher, with the majority of double infection (69.88%), and HPV42 and 56 were the most common co-infection types. HPV16 (31.82%), HPV51 (27.27%) and HPV18 (13.64%) were higher in cervical intraepithelial neplasia grade 1, HPV16 (57.14%) was higher in cervical intraepithelial neplasia grade 2, and HPV16 (55.56%) and HPV18 (33.33%) were higher in cervical intraepithelial neplasia grade 3 or worse. Results from the multivariate logistic regression analysis showed that higher education, menopause, and syphilis infection increased the HPV infection. Conclusions: The most common prevalence genotypes of HR-HPV among Kazak women were HPV16, HPV51, and HPV52. The infection rate of HR-HPV among Kazak women was correlated with education level, menopausal status, and syphilis infection. Measures should be taken targeting high-risk factors. This result suggests that STD patients and women aged 50 and above should be encouraged for screening.