Modeling Auger Processes with Nonadiabatic Molecular Dynamics

Auger-type energy exchange plays key roles in the carrier dynamics in nanomaterials due to strong carrier-carrier interactions. However, theoretical descriptions are limited to perturbative calculations of scattering rates on static structures. We develop an accurate and efficient ab initio technique to model Auger scattering with nonadiabatic molecular dynamics. We incorporate the many-body Coulomb matrix into several surface hopping methods and describe simultaneously charge-charge and charge-phonon scattering in the time-domain and in a nonperturbative, configuration-dependent manner. The approach is illustrated with a CdSe quantum dot. Auger scattering between electrons and holes breaks the phonon bottleneck to electron relaxation. The bottleneck is recovered when electrons and holes are decoupled. The simulations correctly reproduce all experimental processes and time scales, including Auger- and phonon-assisted cooling of hot electrons, intraband carrier relaxation, and carrier recombination. Providing detailed insights into the energy flow, the developed method allows studies of carrier dynamics in nanomaterials with strong carrier-carrier interactions.

Outcomes following emergency colorectal cancer presentation in the elderly

AIM

Colorectal cancer is predominantly a disease of the elderly and up to 30% of these patients will present as an emergency. We compared the outcomes of 'elderly' patients presenting to our unit with a colorectal cancer emergency over a 10-year period with those of a 'younger' cohort.

METHODS

A single centre retrospective review of colorectal cancer emergencies between 1 April 2007 and 1 April 2017 was performed. Patients were separated into two cohorts: 'young' (< 75 years) and 'elderly' (≥ 75 years). Data collected included demographics, disease status, treatment and outcomes.

RESULTS

A total of 341 patients (< 75 years: n = 154; ≥ 75 years: n = 187) presented as a colorectal cancer emergency. Significantly fewer 'elderly' patients underwent curative surgical procedures (72% vs 49%, P < 0.0001) or received adjuvant chemotherapy (56% vs 21%, P < 0.0001). 'Elderly' patients had significantly more postoperative cardio-respiratory complications (7% vs 36%, P < 0.0001), but despite this there was no significant difference in 30-day mortality (7% vs 12%) and survival rates at 1 year (75% vs 74%) or 3 years (56% vs 49%). Elderly patients treated with best supportive care had a median overall survival of just 62 (range 1-955) days.

CONCLUSION

Patients ≥ 75 years presenting as a colorectal cancer emergency were significantly less likely to undergo emergency curative surgery or receive adjuvant chemotherapy than those < 75 years. However, the 30-day mortality, 1- and 3-year survival rates for patients undergoing curative surgery were comparable.

Obesity prevalence and risks among Chinese adults: findings from China PEACE Million Persons Project, 2014–2018

Background

With demographic and epidemiologic transitions, China has become home to the greatest number of obese individuals in the world. Effective policy intervention requires a contemporary assessment of obesity across broad socio-demographic subgroups.

Purpose

We aim to assess the prevalence of overall and abdominal obesity by socio-demographic characteristics and the associations of these characteristics with obesity in China.

Methods

Using the data of 2.7-million community-dwelling participants aged 35–75 years in the China PEACE Million Persons Project, a nationwide cross-sectional screening project from 2014 to 2018, we calculated the prevalence of overall and abdominal obesity based on national guideline definitions (body mass index ≥28 kg/m2, waist circumference ≥85/90 cm for women/men). We examined 12 available socio-demographic variables that are potentially associated with obesity, in addition to self-reported co-morbidities, and quantified the associations of these socio-demographic characteristics with obesity using multivariable mixed models.

Results

The prevalence of overall and abdominal obesity were 15.8% and 37.6% in women and 15.0% and 36.3% in men (Figure). Compared to individuals with normal weight, those with overall obesity had a higher prevalence of hypertension, dyslipidemia, and diabetes (in women: by 30.4, 16.1, and 6.0 percent points; in men, by 29.9, 31.2, and 5.8 percent points). A similar pattern was observed with abdominal obesity. In women, those aged 55–64 years constituted the largest age group with overall and abdominal obesity (33.7% and 35.0%), while in men, those aged 45–54 and 55–64 years constituted the largest age group with overall obesity (30.4%) and abdominal obesity (30.5%), respectively. Older women were at substantially higher risk for obesity (e.g., adjusted relative risk [95% CI] of women aged 65–75 vs. 35–44 years: 1.29 [1.27–1.31] for overall obesity and 1.76 [1.74–1.77] for abdominal obesity) while older men were not. Higher education was associated with lower risk in women (e.g., those with college or university education vs. less than primary school: 0.47 [0.46–0.48] for overall obesity and 0.61 [0.60–0.62] for abdominal obesity) but higher risk in men (1.07 [1.05–1.10] and 1.17 [1.16–1.19]). In both women and men, current smoking was associated with lower risk for obesity, and current drinking was associated with higher risk, but the magnitude of associations was smaller in women than men.

Conclusions

In China, over one in seven individuals meet criteria for overall obesity, and one in three for abdominal obesity. Wide variation exists across socio-demographic subgroups. The associations of age and education with obesity are significant and differ by sex. Understanding obesity in contemporary China has broad domestic policy implications and provides a valuable international reference.

Figure 1

Funding Acknowledgement

Type of funding source: Other. Main funding source(s): The National Key Research and Development Program from the Ministry of Science and Technology of China, the CAMS Innovation Fund for Medical Science

Recent progress on the Chinese space programme and radiation research

Manned space exploration was initiated in China in 1992, and substantial progress has been made. The next step is to build the Chinese Space Station (CSS), which is planned to be launched in 2020. The CSS will provide an on-orbit laboratory for experimental studies including space radiation research. The health risk of space radiation, especially carcinogenesis, is a major concern for long-term space exploration. Establishing a risk assessment system suitable for Chinese astronauts and developing effective countermeasures are major tasks for Chinese space radiobiologists. The Institute of Space Life Sciences, Soochow University has focused on these topics for years. We established cancer models with low-dose-rate exposure of alpha particles, and elucidated a microRNA-TGFβ network regulating bystander effects and a lncRNA-cytoskeleton network regulating genomic instability induced by ionising radiation. We also confirmed the radioresistance of quiescent cells, which inspires a potential strategy to improve individual radioresistance during long-term space travel. However, we believe that a multi-disciplinary strategy must be developed to protect astronauts from highly energised space radiation.

Biportal endoscopic decompression vs. microscopic decompression for lumbar canal stenosis: A systematic review and meta-analysis

Lumbar decompressive surgery is the gold standard treatment for lumbar spinal stenosis. Minimally invasive surgical techniques have been introduced with the aim of reducing the morbidity associated with open surgery. The purpose of the present study was to systematically search the literature and perform a meta-analysis of studies comparing the outcomes between biportal endoscopic technique and microscopic technique for lumbar canal stenosis decompression. A comprehensive search of the PubMed, Google Scholar, Web of Science, Embase and the Cochrane Library databases was performed to identify relevant articles up to 15th of December 2019. Eligible studies were retrieved, data were extracted by two authors independently and risks of bias were assessed. A total of six studies involving 438 patients were selected for review. The results of the pooled analysis indicated similar operative times [mean difference (MD), -3.41; 95% CI, -10.78-3.96; P<0.36], similar complications (MD, 0.70; 95% CI, 0.33-1.46; P=0.34), similar visual analogue scale scores for back and leg pain at the time of the final follow-up and similar Oswestry disability indexes (MD, -0.28; 95% CI, -1.25-0.69; P=0.58) for the two procedures. In conclusion, biportal endoscopic technique is a viable alternative to microscopic technique for lumbar canal stenosis decompression with similar operative time, clinical outcomes and complications.

Down-regulation of UBA6 exacerbates brain injury by inhibiting the activation of Notch signaling pathway to promote cerebral cell apoptosis in rat acute cerebral infarction model

This study aimed to examine the UBA6 role in brain injury mediated by acute cerebral infarction (ACI). In order to screen potential therapeutic targets for ACI, two expression profiles, including GSE97537 and GSE97533 datasets, were downloaded from the GEO database. The Venn method to identify the common DEGs. 68 up-regulated overlapping DEGs and 51 down-regulated overlapping DEGs were used to construct the PPI network by STRING online database. UBA6 was identified as a hub gene by the CytoHubba plugin from Cytoscape. GO and KEGG pathway enrichment analyses were conducted using DAVID online website. UBA6 knockout exacerbated MCAO-mediated brain injury and cell apoptosis in rat brain tissues by H&E and TTC staining and TUNEL assay. The results of flow cytometry and western blot assays further demonstrated that UBA6 inhibition induced the apoptosis of hippocampal neurons and increased cleaved-caspase-3/9 protein levels. Notch1, NICD and Hes1 protein levels were suppressed by down-regulated UBA6. UBA6 was lowly expression in poor prognosis group of 100 patients with ACI. Logistic regression analysis indicated that hypertension, blood glucose, urokinase dose, UBA6 expression and AF were the main risk factors of poor prognosis after thrombolytic therapy for patients with ACI. The ROC curve analysis showed that the sensitivity and specificity of UBA6 was good (sensitivity 100%, specificity 89%, and AUC = 0.772) to be used to evaluate the poor prognosis of ACI. In conclusion, down-regulated UBA6 intensified MCAO-induced brain injury by inhibiting the activation of Notch signaling pathway to promote the apoptosis of hippocampal neurons and was used to predict the poor prognosis of ACI.

Functional cell phenotype induction with TGF-β1 and collagen-polyurethane scaffold for annulus fibrosus rupture repair

Appropriate cell sources, bioactive factors and biomaterials for generation of functional and integrated annulus fibrosus (AF) tissue analogues are still an unmet need. In the present study, the AF cell markers, collagen type I, cluster of differentiation 146 (CD146), mohawk (MKX) and smooth muscle protein 22α (SM22α) were found to be suitable indicators of functional AF cell induction. In vitro 2D culture of human AF cells showed that transforming growth factor β1 (TGF-β1) upregulated the expression of the functional AF markers and increased cell contractility, indicating that TGF-β1-pre-treated AF cells were an appropriate cell source for AF tissue regeneration. Furthermore, a tissue engineered construct, composed of polyurethane (PU) scaffold with a TGF-β1-supplemented collagen type I hydrogel and human AF cells, was evaluated with in vitro 3D culture and ex vivo preclinical bioreactor-loaded organ culture models. The collagen type I hydrogel helped maintaining the AF functional phenotype. TGF-β1 supplement within the collagen I hydrogel further promoted cell proliferation and matrix production of AF cells within in vitro 3D culture. In the ex vivo IVD organ culture model with physiologically relevant mechanical loading, TGF-β1 supplement in the transplanted constructs induced the functional AF cell phenotype and enhanced collagen matrix synthesis. In conclusion, TGF-β1-containing collagen-PU constructs can induce the functional cell phenotype of human AF cells in vitro and in situ. This combined cellular, biomaterial and bioactive agent therapy has a great potential for AF tissue regeneration and rupture repair.

Risk factors for gallstone disease in Shanghai: An observational study

The purpose of this study was to evaluate related risk factors for gallstone disease in Shanghai.We analyzed successive physical examinations of 2288 adults who were recruited at the Jinshan Branch of the Sixth People's Hospital of Shanghai and Jinshan Hospital Affiliated to Fudan University Hospital from July 2010 to December 2012. The odds ratios (ORs) with 95% confidence intervals (CIs) were used to measure the influence factors on the risks of gallstone development.The incidence of gallstone disease was 4.11% (94/2,288). Older age (OR: 1.02; 95% CI: 1.00-1.03; P = .039), higher body weight (OR: 1.02; 95% CI: 1.00-1.04; P = .021), alanine transaminase activity (ALT) (OR: 1.02; 95% CI: 1.01-1.03; P = .001), total standard bicarbonate (SB) (OR: 1.04; 95% CI: 1.02-1.06; P < .001), free SB (OR: 1.17; 95% CI: 1.12-1.21; P < .001), and low density lipoprotein (LDL) levels (OR: 1.59; 95% CI: 1.32-1.91; P < .001) were associated with an increased risk of gallstone disease. Based on univariate logistic analysis, increased triglyceride (TG) levels were associated with a reduced risk of gallstone disease (OR: 0.76; 95% CI: 0.60-0.97; P = .024). The results of multivariable logistic regression analysis showed higher LDL levels correlated with an increased risk of gallstone disease (OR: 1.92; 95% CI: 1.31-2.81; P < .001), while age, weight, ALT, total SB, free SB, and TG levels did not affect the risk of gallstone disease.The although unadjusted results showed age, weight, ALT, total SB, free SB, TG, and LDL levels to be associated with the risk of gallstone disease, adjusting for potential factors revealed only increased LDL levels to be associated with an increased risk of gallstone disease.

Piperine, a functional food alkaloid, exhibits inhibitory potential against TNBS-induced colitis via the inhibition of IκB-α/NF-κB and induces tight junction protein (claudin-1, occludin, and ZO-1) signaling pathway in experimental mice

BACKGROUND

Inflammatory bowel disease is a chronic immunoinflammatory disease of the gastrointestinal tract. Piperine, an alkaloid, has been reported to possess antioxidant, anti-inflammatory, antiapoptotic, and antiulcer potential.

AIM

To elucidate the plausible mechanisms of action of piperine on experimental trinitrobenzenesufonic acid (TNBS)-induced colitis by assessing various biochemical, molecular, histological, and ultrastructural modifications.

METHODS

Colitis was induced in male Sprague-Dawley rats via intrarectal instillation of TNBS. Then, the rats were treated with piperine (10, 20, and 40 mg/kg, p.o.) for 14 days.

RESULTS

TNBS induced significant (p < 0.05) colonic damage, which was assessed by disease activity index, macroscopic score, and stool consistency. The administration of piperine (20 and 40 mg/kg) significantly inhibited (p < 0.05) these damages. Treatments with piperine (20 and 40 mg/kg) notably inhibited (p < 0.05) the TNBS-induced elevation of oxido-nitrosative stress (superoxide dismutase, glutathione, malondialdehyde, and nitric oxide), 5-hydroxytryptamine, and hydroxyproline content in the colon. Furthermore, colonic inducible nitric oxide synthase (iNOs), tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1β, IL-6, interferon-gamma, and cyclooxygenase-2 (COX-2) messenger RNA (mRNA) expressions were upregulated after TNBS instillation and piperine (20 and 40 mg/kg) significantly attenuated (p < 0.05) these elevated mRNA expressions. TNBS decreased the expressions of tight junction (TJ) protein (claudin-1, occludin, and zonula occludens-1 (ZO-1)) and increased the expressions of proapoptotic (caspase-1) protein. These expressions were markedly inhibited (p < 0.05) by piperine treatment. Histological and ultrastructural studies of transmission electron microscopy suggested that piperine significantly ameliorated (p < 0.05) TNBS-induced colonic aberrations.

CONCLUSION

Piperine ameliorated the progression of TNBS-induced colitis by modulating the nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor-alpha/nuclear factor-kappa B signaling pathway, thus inhibiting the overexpression of proinflammatory cytokines (TNF-α and IL's), COX-2, iNOs, oxido-nitrosative stress, and proapoptotic proteins (caspase-1) that may improve the expression of TJ protein (claudin-1, occludin, and ZO-1).

Electron-Phonon Scattering Is Much Weaker in Carbon Nanotubes than in Graphene Nanoribbons

Carbon nanotubes (CNTs) and graphene nanoribbons (GNRs) are lower-dimensional derivatives of graphene. Similar to graphene, they exhibit high charge mobilities; however, in contrast to graphene, they are semiconducting and thus are suitable for electronics, optics, solar energy devices, and other applications. Charge carrier mobilities, energies, and lifetimes are governed by scattering with phonons, and we demonstrate, using ab initio nonadiabatic molecular dynamics, that charge-phonon scattering is much stronger in GNRs. Focusing on a GNR and a CNT of similar size and electronic properties, we show that the difference arises because of the significantly higher stiffness of the CNT. The GNR undergoes large-scale undulating motions at ambient conditions. Such thermal geometry distortions localize wave functions, accelerate both elastic and inelastic charge-phonon scattering, and increase the rates of energy and carrier losses. Even though, formally, both CNTs and GNRs are quantum confined derivatives of graphene, charge-phonon scattering differs significantly between them. Showing good agreement with time-resolved photoconductivity and photoluminescence measurements, the study demonstrates that GNRs are quite similar to molecules, such as conjugated polymers, while CNTs exhibit extended features attributed to bulk materials. The state-of-the-art simulations alter the traditional view of graphene nanostructures and demonstrate that the performance can be tuned not only by size and composition but also by stiffness and response to thermal excitation.

The development of a rapid and highly sensitive monitoring system for radioxenon isotopes

The rapid monitoring of radioactive gas is one of the most direct and sensitive methods used to characterize the leakage of nuclear installations, and its technical difficulty lies in achieving the goals of rapid and high sensitivity as much as possible. Several techniques, including adsorption at ultralow temperatures, impurity removal with hollow fiber membranes, and on-site measurements with low background, were used to develop a rapid and highly sensitive monitoring system for radioxenon isotope. This system could simultaneously separate xenon from air and measure radioxenon isotopes in a rapid and efficient way. The technical specifications of this system are as follows: the recovery of stable xenon is greater than 70%; and the MDCs of ¹³³Xe and ¹³⁵Xe are 4.3 Bq/m³ and 0.4 Bq/m³ within a 30 min cycle of sampling and testing, respectively. It is worth noting that the MDC of ¹³³Xe here is only approximately 1/18000 to 1/800 of those obtained with other similar equipment, and the monitoring period of this system is one fortieth of that of noble gas equipment for OSI, for example, XESPM-III. As a result, the standard uncertainties are less than 16%. The system developed in this paper can be applied in leakage monitoring of nuclear facilities and can also provide instructive technical support for other tests, such as nuclear safety monitoring and evaluation.

The human imperative of stabilizing global climate change at 1.5°C

Increased concentrations of atmospheric greenhouse gases have led to a global mean surface temperature 1.0°C higher than during the pre-industrial period. We expand on the recent IPCC Special Report on global warming of 1.5°C and review the additional risks associated with higher levels of warming, each having major implications for multiple geographies, climates, and ecosystems. Limiting warming to 1.5°C rather than 2.0°C would be required to maintain substantial proportions of ecosystems and would have clear benefits for human health and economies. These conclusions are relevant for people everywhere, particularly in low- and middle-income countries, where the escalation of climate-related risks may prevent the achievement of the United Nations Sustainable Development Goals.

The human imperative of stabilizing global climate change at 1.5°C

Increased concentrations of atmospheric greenhouse gases have led to a global mean surface temperature 1.0°C higher than during the pre-industrial period. We expand on the recent IPCC Special Report on global warming of 1.5°C and review the additional risks associated with higher levels of warming, each having major implications for multiple geographies, climates, and ecosystems. Limiting warming to 1.5°C rather than 2.0°C would be required to maintain substantial proportions of ecosystems and would have clear benefits for human health and economies. These conclusions are relevant for people everywhere, particularly in low- and middle-income countries, where the escalation of climate-related risks may prevent the achievement of the United Nations Sustainable Development Goals.

Core-dependent properties of copper nanoclusters: valence-pure nanoclusters as NIR TADF emitters and mixed-valence ones as semiconductors

While valence-pure copper alkynyl nanoclusters show near-infrared TADF, the mixed-valence ones exhibit semiconductivity.

We report herein that copper alkynyl nanoclusters show metal-core dependent properties via a charge-transfer mechanism, which enables new understanding of their structure–property relationship. Initially, nanoclusters 1 and 2 bearing respective Cu(i)₁₅ (C1) and Cu(i)₂₈ (C2) cores were prepared and revealed to display near-infrared (NIR) photoluminescence mainly from the mixed alkynyl → Cu(i) ligand-to-metal charge transfer (LMCT) and cluster-centered transition, and they further exhibit thermally activated delayed fluorescence (TADF). Subsequently, a vanadate-induced oxidative approach to in situ generate a nucleating Cu(ii) cation led to assembly of 3 and 4 featuring respective [Cu(ii)O₆]@Cu(i)₄₇ (C3) and {[Cu(ii)O₄]·[VO₄]₂}@Cu(i)₄₆ (C4) cores. While interstitial occupancy of Cu(ii) triggers inter-valence charge-transfer (IVCT) from Cu(i) to Cu(ii) to quench the photoluminescence of 3 and 4, such a process facilitates charge mobility to render them semiconductive. Overall, metal-core modification results in an interplay between charge-transfer processes to switch TADF to semiconductivity, which underpins an unusual structure–property correlation for designed synthesis of metal nanoclusters with unique properties and functions.

[Practice and application of enhanced recovery after surgery in perioperative period of liver operation]

Objective: To investigate the feasibility and safety of enhanced recovery after surgery (ERAS) in perioperative period of liver operation. Methods: One hundred and sixty-six patients who underwent liver operation were enrolled as control group, and additional 170 patients were chosen as ERAS group. Preoperative and postoperative indexes of the two groups were compared. Results: Compared with the control group, patients in ERAS group had higher preoperative enteral nutrition support rate, lower incidence of thirst and hunger, earlier initial postoperative feeding, higher prophylactic analgesia rate, lower incidence of outbreak pain, more daily activities, lower incidence of abdominal distention and shorter hospitalization days (all P<0.05). Conclusion: Application of enhanced recovery after surgery on perioperative nursing care in elective liver surgical patients is safe, and it can relieve patients' perioperative discomfort and accelerate postoperative rehabilitation.

Susceptibility of Anopheles gambiae complex mosquitoes to microbial larvicides in diverse ecological settings in western Kenya

The microbial larvicides Bacillus thuringiensis var. israelensis (Bti) and Bacillus sphaericus (Bs) (Bacillales: Bacillaceae) are well known for their efficacy and safety in mosquito control. In order to assess their potential value in future mosquito control strategies in western Kenya, the current study tested the susceptibility of five populations of Anopheles gambiae complex mosquitoes (Diptera: Culicidae), collected from five diverse ecological sites in this area, to Bti and Bs under laboratory conditions. In each population, bioassays were conducted with eight concentrations of larvicide (Bti/Bs) in four replicates and were repeated on three separate days. Larval mortality was recorded at 24 h or 48 h after the application of larvicide and subjected to probit analysis. A total of 2400 An. gambiae complex larvae from each population were tested for their susceptibility to Bti and Bs. The mean (± standard error of the mean, SEM) lethal concentration values of Bti required to achieve 50% and 95% larval mortality (LC₅₀ and LC₉₅ ) across the five populations were 0.062  (± 0.005) mg/L and 0.797 (± 0.087) mg/L, respectively. Corresponding mean  (± SEM) values for Bs were 0.058 (± 0.005) mg/L and 0.451 (± 0.053) mg/L, respectively. Statistical analysis indicated that the five populations of An. gambiae complex mosquitoes tested were fully susceptible to Bti and Bs, and there was no significant variation in susceptibility among the tested populations.