Ratio Of Rate Research Articles

Effect of obstruction ratio rate of change gradients on the deflagration characteristics of H2-Air premixed gases

To investigate the effect of the gradient of obstruction ratio change rate on the H2-Air premixed gas combustion explosion in the semi-confined space, Fluent software is used to simulate the explosion flame, turbulent turning and pressure wave coupling process under the conditions of obstacles with different obstruction ratios change rate. The results indicate that as the obstruction ratio's rate of change increases, flame propagation speed decreases, while pressure peak and pressure change rate increase. The flame front becomes sharper, and a positive change in obstruction ratio more significantly affects flame shape and speed than a negative change. At obstruction ratio change rates of −0.3 and −0.2, the flame front area and peak area reach their maximum values. At a change rate of 0.3, the pressure peak is 232 kPa, and the maximum pressure change is 126 kPa/ms, indicating the explosion intensity reaches its peak.

Immunogenicity of a booster dose of a bivalent (Asp614Gly and omicron BA.4/5 variant) self-amplifying mRNA SARS-CoV-2 booster vaccine versus the BNT162b2 omicron BA.4/5 mRNA vaccine: a randomised phase 3 trial

We previously showed that ARCT-154, a self-amplifying mRNA COVID-19 vaccine, had improved immunogenicity and antibody persistence compared with conventional mRNA or adenovirus vector vaccines. In this study, we compared ARCT-2301, a bivalent self-amplifying mRNA vaccine (Asp614Gly and omicron BA.4/5 variant), with the bivalent Comirnaty omicron BA.4-5 vaccine, to determine whether this improved response persisted in bivalent formulations against different SARS-CoV-2 variants. This randomised, multicentre, phase 3, observer-masked, active-controlled comparative study was done at nine hospitals in Japan. Eligible participants were healthy Japanese adults, aged at least 18 years, who had previously received a full immunisation series of three to five doses of mRNA COVID-19 vaccines (Comirnaty or Spikevax [Moderna]), with the last dose received at least 3 months before screening for this trial. Participants were randomly assigned (1:1) to either ARCT-2301 or Comirnaty BA.4-5 mRNA vaccine using interactive computer-generated randomisation with a block size of four. Randomisation was stratified by gender (men vs women), age group (<65 years vs ≥65 years), type of vaccine used for last vaccination (bivalent omicron BA.1 vs bivalent omicron BA.4/5), and time since last COVID-19 vaccination (<5 months vs ≥5 months). ARCT-2301 was supplied in vials containing 100 μg lyophilised mRNA, 50 μg mRNA each coding for the full-length spike proteins of the ancestral Asp614Gly SARS-CoV-2 strain and omicron BA.4/5 variant. Immediately before use, each vial was reconstituted with 10 mL saline. The comparator original omicron BA.4/5 mRNA vaccine (Comirnaty BA.4-5) was supplied in ready-to-use vials containing a single dose of 30 μg mRNA in 0·3 mL volume. Both vaccines were administered by intramuscular injection in the deltoid of the non-dominant arm. The primary outcome of the study was to show non-inferiority of immunogenicity of ARCT-2301 versus Comirnaty BA.4-5 at day 29 as neutralising antibody geometric mean titres (GMT) and seroresponse rates against omicron BA.4/5. Primary analyses were done in a per-protocol manner. The trial is registered with the Japan Registry for Clinical Trials, jRCT2031230340. Between Sept 29 and Nov 18, 2023, we enrolled 930 participants (451 men and 479 women) to receive a booster dose of ARCT-2301 (n=465) or Comirnaty BA.4-5 (n=465). The primary immunogenicity outcome to show that the antibody response at day 29 against omicron BA.4/5 elicited by ARCT-2301 was non-inferior to that elicited with Comirnaty BA.4-5 was achieved, both by GMT ratio (1·49, 95% CI 1·26-1·76) and difference in seroresponse rate (7·2%, 95% CI 0·6-13·7). Furthermore, the differences in antibody response between the groups showed superiority for ARCT-2301 against Wuhan-Hu-1 using both criteria, with a GMT ratio of 1·45 (95% CI 1·28-1·63) and a difference in seroresponse rate of 12·5% (95% CI 5·9-19·0), and omicron XBB.1.5, with a GMT ratio of 1·63 (95% CI 1·36-1·94) and a seroresponse rate difference of 16·7% (95% CI 10·1-23·2). Both vaccines were well-tolerated with mainly mild, transient solicited adverse events and no causally related severe or serious adverse events. Boosting mRNA-immunised adults with ARCT-2301 induced superior immunogenicity compared with Comirnaty BA.4-5 against both Wuhan-Hu-1 and omicron BA.4/5 variant COVID-19, and elicited a higher response against omicron XBB.1.5. Both vaccines had similar tolerability profiles. Self-amplifying mRNA vaccines could provide a substantial contribution to pandemic preparedness and response, inducing robust immune responses with a lower dose of mRNA to allow wider and more equitable distribution. Japanese Ministry of Health, Labour, and Welfare and Meiji Seika Pharma.

Enhancing bending strength in continuous drive friction welding of PEEK polymer cylinders through the innovative progressively increased welding area method

The continuous drive friction welding (CDFW) stands out for its low energy consumption within the welding realm. Polyetheretherketone (PEEK) represents a high-performance engineering thermoplastic, falling under the polyaryletherketone family. Renowned for its outstanding mechanical, thermal, and chemical attributes, PEEK finds utility across a diverse array of industries. However, the discovery of numerous voids at the weld interface has revealed limitations in the mechanical properties of PEEK welded samples. This study introduces an innovative approach named progressively increased welding area (PIWA) method, to mitigate voids within the weld interface. In general, the Taguchi method was used to optimize the process parameters of CDFW of dissimilar PEEK round rods to reduce random efforts by the trial-and-error method. It was found that the proposed PIWA method can definitely enhance the bending strength of rotational friction welded samples due to reduction of voids inside the weld interface. The optimal process parameters for the CDFW with the PIWA method involve a rotational speed of 2500 rpm, a cone angle of 120°, a cone top width of 8 mm, and a feed rate of 0.1 mm/s. The most influential factor affecting the bending strength of the PEEK welded samples is the feed rate, followed by cone angle, rotational speed, and cone top width. Specifically, the contribution ratios for feed rate, cone angle, rotational speed, and cone top width are about 71 %, 20 %, 7 %, and 2 %, respectively. The confirmation tests showed that the bending strength of the PEEK welded samples using optimal process parameters can be increased by approximately 68 % compared with the maximum bending strength of 180 MPa using the conventional method with a cone angle of 180° The proposed PIWA method has industrial applicability and practical value because this technique can enhance the mechanical properties of PEEK welded samples under low environmental pollution and energy consumption.

Evaluation of immune checkpoint inhibitors for colorectal cancer: A network meta‑analysis.

Colorectal cancer (CRC) is challenging to treat due to its high metastatic rate. Recent strategies have focused on combining immune checkpoint inhibitors (ICIs) with other treatments. The aim of the present study was to conduct a network meta-analysis of randomized controlled trials (RCTs) to assess the efficacy and adverse effects of different ICI treatments for CRC. A literature search for RCTs was conducted using PubMed, the Cochrane Library, Embase, ClinicalTrials.gov and Web of Science databases, covering the period from the inception of each database until April 2024. A total of 12 RCTs involving 2,050 participants were selected for inclusion in the analysis. The network meta-analysis employed the MetaInsight tool to assess multiple endpoints. The criteria for study selection were based on the Population, Intervention, Comparison, Outcome and Studies framework as follows: i) Population, patients with CRC; ii) intervention, studies using ICI to treat CRC; iii) comparison, active comparators, including placebo; iv) outcome, overall survival, progression-free survival, objective response rate and adverse events; and v) study design, RCTs. The results of the analysis revealed that programmed cell death-ligand 1 (PD-L1) inhibitors significantly improved overall survival time [mean difference (MD), 2.28 months; 95% confidence interval (CI), 0.44 to 4.11], while programmed cell death protein 1 (PD-1) inhibitors exhibited a superior progression-free survival time (MD, 4.79 months; 95% CI, 3.18 to 6.40) compared with active comparators. However, none of the ICI treatments had significant differences in odds ratios for the objective response rate and adverse events compared with active comparators. These findings indicate that treatment with PD-L1 and PD-1 inhibitors improved the overall survival time and delayed disease progression in patients with CRC. These findings offer valuable insights for future research aimed at improving CRC patient outcomes.

Tidal Disruption Events from Stripped Stars

Observations of tidal disruption events (TDEs) show signs of nitrogen enrichment reminiscent of other astrophysical sources such as active galactic nuclei and star-forming galaxies. Given that TDEs probe the gas from a single star, it is possible to test whether the observed enrichment is consistent with expectations from the CNO cycle by looking at the observed nitrogen/carbon (N/C) abundance ratios. Given that ≈20% of solar-mass stars (and an even larger fraction of more massive stars) live in close binaries, it is worthwhile to also consider what TDEs from stars influenced by binary evolution would look like. We show here that TDEs from stars stripped of their hydrogen-rich (and nitrogen-poor) envelopes through previous binary-induced mass loss can produce much higher observable N/C enhancements than even TDEs from massive stars. Additionally, we predict that the time dependence of the N/C abundance ratio in the mass fallback rate of stripped stars will follow the inverse behavior of main-sequence stars, enabling a more accurate characterization of the disrupted star.

Interaction between shallow and deep structures: Forward-modeling kinematics sequence of a fold-and-thrust belt with double detachment

It is crucial to determine the sequence of deformation and the interaction between shallow and deep structures within the multiple detachment systems to comprehend geological processes fully in fold-and-thrust belts (FTBs). Here, we implement forward modeling to investigate the geometric, kinematic, and syntectonic sedimentary characteristics of shallow and deep structural interactions. We design four combinative patterns of geometric structures, three kinematic sequence scenarios, and two settings with different ratios of the sedimentation rate to the uplift rate to examine the influence of such settings on growth strata geometry. The most effective results of 24 groups of shallow and deep structural interactions were obtained for various combinations of fault-bend fold, detachment fold, and tectonic wedge. This study provides a sequential kinematic image of FTBs, illustrating the interaction of two sets of detachments and demonstrating how different styles of pre- and growth strata can be utilized to identify shallow and deep structure deformation processes. The geometry of pre- and growth strata observed in the models is similar to that observed in natural structures. These forward models facilitate a better understanding of the complex geometry and kinematics of the interaction between shallow and deep fault-related folds.

Preimplantation Genetic Testing for Aneuploidy in In Vitro Fertilization Using Comprehensive Chromosome Screening: A Systematic Review and Meta-Analysis.

The utility of pre-implantation genetic testing (PGT-A) is controversial, with older meta-analyses demonstrating improved pregnancy outcomes, while newer trials have not shown benefit. Therefore, we performed a meta-analysis which aimed to evaluate the benefits of PGT-A using comprehensive chromosome screening (CCS) and its effects on in vitro fertilization (IVF) outcomes among randomized controlled trials (RCTs). We conducted a systematic search to identify RCTs comparing women undergoing PGT-A with CSS with women not undergoing PGT-A, from inception to December 2020. Random effects meta-analysis was utilized to calculate average odds ratios (OR) for clinical pregnancy rate (CPR), ongoing pregnancy rate (OPR), and miscarriage rate (MR). The heterogeneity of exposure was assessed using Forest plots and I2 statistics. Publication bias was evaluated using Egger's test. Among 1251 citations, seven RCTs met the inclusion criteria. Biopsies of embryos were carried out at various developmental stages, including polar body, day 3, and day 5-6 of culture. Data was analyzed as all studies and blastocyst only. Meta-analysis failed to show improvement in OPRs using PGT-A in the all ages, <35 years old and ≥35 years old age groups. There was also no significant difference in CPRs in any group. The MR decreased with the use of PGT-A (among all biopsy types and among blastocyst biopsies) in the all-ages group, but not when stratifying according to patient age <35 and ≥35 years old. More data regarding the risks and advantages of PGT-A are needed to make a final decision on the value of this intervention in clinical practice. The exact magnitude of the benefit of PGT-A selection cannot be correctly determined until multiple standardized protocol IVF PGT-A trials are conducted.

Comparative efficacy of pembrolizumab with carboplatin and paclitaxel as first-line (1L) therapy in recurrent/metastatic head and neck squamous cell carcinoma (R/M HNSCC): A network meta-analysis (NMA) with matching-adjusted indirect comparison (MAIC).

e18006 Background: The single-arm, phase IV, KEYNOTE-B10 (KNB10) trial demonstrated the antitumor effect of the KNB10 regimen for 1L treatment of R/M HNSCC. It is critical to understand the comparative efficacy of the KNB10 regimen versus other recommended interventions in 1L R/M HNSCC, using advanced evidence synthesis methodologies, to inform clinical decision making. Methods: A systematic literature review, conducted on October 31, 2023, identified 25 randomized controlled trials evaluating 1L interventions in R/M HNSCC, of which six evaluated recommended interventions and formed a connected network. Of these, KEYNOTE-048 was determined to be the most similar study to the disconnected, single-arm, KEYNOTE-B10 trial. Therefore, individual patient-level data from KEYNOTE-B10 final analysis were reweighted and matched to KEYNOTE-048 via a MAIC in terms of metastatic disease, PD-L1 Combined Positive Score, ECOG performance status, primary tumor location as well as HPV status, sex, race, age, and smoking status. KEYNOTE-B10 was then considered an additional treatment arm of KEYNOTE-048 and was incorporated in the network. Fixed-effect NMA models in Bayesian framework were then used to estimate odds ratios of objective response rate (ORR), with 95% credible intervals, for comparisons between KNB10 and other interventions recommended for 1L R/M HNSCC. Results: Results from the fixed-effects NMA are summarized in the table. For ORR, the KNB10 regimen was more efficacious compared to pembrolizumab+platinum+5-FU, cetuximab+platinum+5-FU, platinum+5-FU, cisplatin+paclitaxel, cisplatin, 5-FU, and methotrexate ( p &lt; 0.05). There was no statistically significant difference in ORR between the KNB10 regimen and cetuximab+cisplatin+docetaxel. Conclusions: This NMA with MAIC suggests patients treated with the KNB10 regimen had improved or comparable ORR outcomes versus other recommended 1L interventions for R/M HNSCC, which further reinforces the combination therapy of pembrolizumab+platinum+taxane as an acceptable alternative 1L treatment option for R/M HNSCC. Future analyses should additionally compare survival outcomes between the KNB10 regimen and other recognized interventions in this patient population. [Table: see text]

Efficacy and Safety of Anti–Programmed Cell Death Protein 1/Programmed Death-Ligand 1 Antibodies Plus Chemotherapy as First-Line Treatment for NSCLC in the People’s Republic of China: a Systematic Review and Meta-Analysis

IntroductionThe available approved anticancer drugs for Chinese patients are relatively limited because of China's low participation rate in international clinical trials. Therefore, a focus on approved anti–programmed cell death protein 1 (PD-1)/programmed death-ligand 1 (PD-L1) drugs in China is needed. This study aims to assess the heterogeneity of anti–PD-1/PD-L1 antibodies manufactured in China (domestic PD-1/PD-L1) and overseas (imported PD-1/PD-L1) when combined with chemotherapy as the first-line treatment of NSCLC. MethodsA systematic search was performed using PubMed, EMBASE, and Cochrane Library of publications up to July 13, 2023. Meta-analysis was applied to compare the efficacy and safety profile between anti–PD-1/PD-L1 antibodies plus chemotherapy (PD-1/PD-L1+Chemo) and chemotherapy alone using STATA software. Pooled hazard ratios for progression-free survival and overall survival, odds ratios for objective response rate, and incidence rate of grade greater than or equal to three treatment-related adverse events with 95% confidence intervals were calculated in the domestic group and imported group by a random-effects model, and the heterogeneity between the two estimates was assessed. ResultsThere were 14 eligible clinical studies with a total of 3951 patients involved in this analysis, including eight studies of domestic PD-1/PD-L1+Chemo and six studies of imported PD-1/PD-L1+Chemo. The study revealed that there was no significant difference between domestic and imported PD-1/PD-L1+Chemo in overall survival (p = 0.80), progression-free survival (p = 0.53), and incidence rate of grade greater than or equal to three treatment-related adverse events (p = 0.10). Nevertheless, the objective response rate of imported PD-1/PD-L1+Chemo was significantly higher than that of domestic PD-1/PD-L1+Chemo (p = 0.03). ConclusionsDomestic anti–PD-1/PD-L1 antibodies plus chemotherapy were found to have comparable efficacy and safety to those combined with imported anti–PD-1/PD-L1 antibodies based on current evidence.

Synthesis of Solvent-Mediated Morphology-Controlled PdSn Alloy Nanocatalysts and their Application in Electrocatalysis of Ethylene Glycol and Ethanol.

2D nanodendrites (NDs) and nanosheets (NSs) have been regarded as efficient nanocatalysts for enhancing the electrocatalytic performance due to their low coordinated sites and abundant electrocatalytic centers. Nevertheless, it remains challenging to construct advanced NDs and NSs in a single reaction system. Herein, by tuning the volume ratios of mixed solvents, the reduction and diffusion rate of Sn2+ on Pd NSs template was rationally controlled to prepare PdSn NDs and PdSn NSs. Ascribed to the open 2D nanostructure, high specific surface area, and robust synergistic effect, the as-prepared PdSn NDs and PdSn NSs exhibited distinguished electrocatalytic activities for ethylene glycol oxidation reaction (EGOR) and ethanol oxidation reaction (EOR), as well as commendable electrocatalytic durability, which were far superior to the Pd NSs and commercial Pd/C. In addition, the PdSn NDs exhibited enhanced reaction kinetics because the characteristic branch structure exposed a high density of active sites. This work may provide significant guidance for preparing excellent nanocatalysts with various morphological features by simply optimizing the content of the coexisting solvents.

Evaluation and model to achieve sex parity in cataract surgical coverage in Theni district, India

Background/aimsTo propose an approach to determine the target ratio of cataract surgical rates (CSRs) of female to male subpopulations to increase sex parity in cataract surgical coverage (CSC), based on...

Mixed‐Dimensional Membranes with Double 0D@2D Structures Enable Efficient and Sustainable Water Treatment

AbstractHigh‐efficiency and sustainable membrane purification technology is highly desirable but unattainable in the field of water treatment. 2D materials are emerging as very promising candidates for water treatment applications. However, membranes assembled by pure 2D materials lack reasonable structural and functional design, usually exhibiting relatively low water permeance, purification performance, and fouling resistance. Here, a mixed‐dimensional membrane is designed to solve the above‐mentioned problems by assembling two kinds of in situ grown 0D@2D functional building blocks of SiO2@GO and TiO2@MXene. Specifically, the obtained membrane exhibits high and maintainable water permeance of 2114 L m−2 h−1 bar−1 as well as high rejection rates toward organic dyes thanks to the plentiful firm water channels constructed by 0D@2D structures and the negative charges on both SiO2@GO and TiO2@MXene, respectively. Moreover, the 0D@2D TiO2@MXene serves as photocatalyst, rendering the composite membrane intriguing self‐cleaning function under UV irradiation, which is verified by the high recovery ratios of water permeance (97.5%) and dye interception rate (98.7%). Thus, this work offers a promising approach for the design of highly efficient and sustainable membrane for separation and purification purposes.

Influence of the substrate conductivity type on the electroluminescence properties of PP+IN and PIN+N diodes based on amorphous silicon carbide (a-Si1-xCx:H) / crystalline silicon (c-Si) heterostructures

The study of the conduction and light emission mechanisms of PIN diodes based on amorphous silicon-carbide (a-Si1-xCx:H) thin film and crystalline silicon (c-Si) substrates is reported in this work. Using the same low-temperature process (200 °C), PP+IN and PIN+N structures were fabricated on p-type and n-type silicon (Si) substrates, respectively. The plasma enhanced chemical vapor deposition (PECVD) technique was employed for the active layers deposition where two different CH4/SiH4 flow rates ratios of 30 sccm/6 sccm and 30 sccm/1 sccm were used. All structures show red-orange light emission in forward bias (FB). The structures with the active layer deposited with a lower SiH4 flow rate, display light emission with a higher intensity at a lower voltage bias.In addition, we related the current-voltage measurements with different conduction models and the dominant charge transport mechanisms in the PIN structures were proposed. The highest Si content structures were related to Fowler-Nordheim (F-N) tunneling, because of its active layer with lower barrier height. On the other hand, the lowest Si content structures were associated with the Poole-Frenkel (P-F) emission, due to a higher density of defects in localized tail states. The results showed the same conduction and emission mechanisms for the PP+IN and PIN+N diodes with the same active layer, regardless of the conduction type of substrate, proving that it is feasible to use the same process for developing light emission devices on p-type and n-type Si substrates.

Years of Potential Life Lost due to COVID-19 according to race/color and gender in Brazil between 2020 and 2021.

Mortality caused by the COVID-19 pandemic has impacted indicators of Years of Potential Life Lost (YPLL) worldwide. This study aimed to estimate the YPLL due to mortality caused by COVID-19, according to sex, age group, and race/color in Brazil, from March 2020 to December 2021. Deaths caused by COVID-19 were characterized, in which the rates and ratios of standardized YPLL rates, the average number of years of potential life lost (ANYPLL), and the average age at death (AAD) were estimated and compared. Overall, 13,776,969.50 potential years of life were lost, which resulted in an average loss of 22.5 potential years not lived. A greater loss of potential years of life was identified in men (58.12%) and in the age groups from 0 to 59 years in the black (58.92%) and indigenous (63.35%) populations, while in the age groups of 60 years and over, a greater loss of YPLL was observed in the white (45.89%) and yellow (53.22%) populations. Women recorded the highest ADD, with the exception of indigenous women. White men (1.63), brown men (1.59), and black men (1.61) had the highest rates when compared to white women. Although COVID-19 has a greater impact on the elderly, it was the black and indigenous populations under the age of 60 who had the greatest loss of potential years of life.

Simple coiling of middle meningeal artery embolization for chronic subdural hematoma: An inverse probability of treatment weighting matched cohort study.

Middle meningeal artery embolization (MMAE) for chronic subdural hematoma (CSDH) has gained much attention in recent years. However, unintended embolization may occur when employing liquid embolic agents or particles. We present our clinical experience in simple coiling of MMAE to manage CSDH. Patients underwent either surgical evacuation or MMAE with simple coiling for CSDH were reviewed. Clinical and radiographic outcomes were assessed at admission, 1-month, and 6-month intervals. Two treatment groups were matched with inverse probability of treatment weighting. One hundred twelve patients were included, with 27 patients in MMAE group and 87 patients in surgery group. In MMAE group, significant reductions were observed in hematoma width (admission vs. 1-month, 2.04 [1.44-2.60] cm vs. 0.62 [0.37-0.95] cm, p < 0.001). The adjusted odds ratio (aOR) of surgical rescue rate (0.77 95%CI 0.13-4.47, p = 0.77), hematoma reduction (>50%) (0.21 95%CI 0.04-1.07, p = 0.06), and midline shift improvement rate (3.22, 95%CI 0.84-12.4, p = 0.09) had no substantial disparities between two groups at 1-month follow-up. In addition, no significant difference was noted between two groups in terms of hematoma reduction (>50%) at 6-month follow-up (aOR 1.09 95%CI 0.32-3.70, p = 0.89). No procedure-related complications were found in MMA embolization group. Simple coiling for MMA had comparable outcomes with surgical evacuation for CSDH. Our findings suggest that simple coiling can be an alternative choice for liquid agents or particles in MMA embolization for CSDH with acceptable safety.

Viral rebound occurrence immediately after drug discontinuation involving neither drug resistance nor latent reservoir

Some viruses exhibit “rebound” when the administration of antiviral drugs is discontinued. Viral rebound caused by resistance mutations or latent reservoirs has been studied mathematically. In this study, we investigated the viral rebound due to other causes. Since immunity is weaker during antiviral treatment than without the treatment, drug discontinuation may lead to an increase in the viral load. We analyzed the dynamics of the number of virus-infected cells, cytotoxic T lymphocytes, and memory cells and identified the conditions under which the viral load increased upon drug discontinuation. If drug is administered for an extended period, a viral rebound occurs when the ratio of viral growth rate in the absence to that in the presence of the antiviral drug exceeds the “rebound threshold.” We analyzed how the rebound threshold depended on the patient's conditions and the type of treatment. Mathematical and numerical analyses revealed that rebound after discontinuation was more likely to occur when the drug effectively reduced viral proliferation, drug discontinuation was delayed, and the processes activating immune responses directly were stronger than those occurring indirectly through immune memory formation. We discussed additional reasons for drugs to cause viral rebound more likely.

Improved high shear mixers enhance fast halogenation reactions of alcohols

In the view of green and sustainable synthesis, there is still a broad space for improvement with respect to the halogenations of the alcohol, which is facing up with the problems of high input and low yield. Herein, high shear mixers (HSM) were exploited first to enhance the bromination of tert-butyl alcohol by improving the mixing performance. Notably, the baffle plate (BP) was first proposed to facilitate the in situ separation of the product from the reaction system, promoting the reversible reaction equilibrium to shift toward the right direction. The influences of the molar ratio of reactants, temperature, feed rate, rotor speed, and height of BP were investigated on the reaction performance, which provides a facile and cost-efficient intensified technology to prepare 2-bromo-2-methylpropane. The maximum yield is achieved as 94.8% using HSM, obviously higher than that using CST (82.6%) and HST-Impeller (87.6%), and the reaction time can be shortened by 75%. Furthermore, such HSM and BP-HSM can successfully improve the yields of some fast alcohol halogenations with shorter reaction time. This ingenious exploration of BP in HSM provides valuable guidance on design new technology to intensify some fast organic chemical reactions with the products immiscible to the reactants.

Evaluating pySTEPS optical flow algorithms for convection nowcasting over the Maritime Continent using satellite data

Abstract. The Maritime Continent (MC) regularly experiences powerful convective storms that produce intense rainfall, flooding and landslides, which numerical weather prediction models struggle to forecast. Nowcasting uses observations to make more accurate predictions of convective activity over short timescales (∼ 0–6 h). Optical flow algorithms are effective nowcasting methods as they are able to accurately track clouds across observed image series and predict forward trajectories. Optical flow is generally applied to weather radar observations; however, the radar coverage network over the MC is not complete and the signal cannot penetrate the high mountainous regions. In this research, we apply optical flow algorithms from the pySTEPS nowcasting library to satellite imagery to generate both deterministic and probabilistic nowcasts over the MC. The deterministic algorithm shows skill up to 4 h on spatial scales of 10 km and coarser and outperforms a persistence nowcast for all lead times. Lowest skill is observed over the mountainous regions during the early afternoon, and highest skill is seen during the night over the sea. A key feature of the probabilistic algorithm is its attempt to reduce uncertainty in the lifetime of small-scale convection. Composite analysis of 3 h lead time nowcasts, initialised in the morning and afternoon, produces reliable ensembles but with an under-dispersive distribution and produces area under the curve scores (i.e. ratio of hit rate to false alarm rate across all probability thresholds) of 0.80 and 0.71 over the sea and land, respectively. When directly comparing the two approaches, the probabilistic nowcast shows greater skill at ≤ 60 km spatial scales, whereas the deterministic nowcast shows greater skill at larger spatial scales ∼ 200 km. Overall, the results show promise for the use of pySTEPS and satellite retrievals as an operational nowcasting tool over the MC.

Diversity of MHC class II DRB alleles in the Northern chamois genus Rupicapra

Abstract Major histocompatibility complex (MHC) genes are commonly used markers for monitoring adaptive genetic and evolutionary potential of species. In this study, we investigated genetic variation of the MHC class II DRB locus in the chamois genus Rupicapra by using next-generation sequencing. Sequencing of 102 samples led to the identification of 25 alleles, 11 of which are novel. The high ratio of the relative rates of nonsynonymous to synonymous mutations (dN/dS) suggests a signal of positive selection on this locus. We analyzed patterns of genetic variation within and among 2 subspecies of Northern Chamois and compared them to previously published studies using neutral markers to provide a basis for assessing the effects of demographic processes. Our analyses have shown that alleles are likely to be maintained by balancing selection in different populations with similar frequencies and that this mechanism also works in small, isolated populations that are strongly affected by genetic drift.

Heavy metal geochemistry and toxicity assessment of water environment from Ib valley coalfield, India: Implications to contaminant source apportionment and human health risks

The present study aims to investigate the hydrogeochemical evolution of heavy metals and assesses impacts of mining activities on the groundwater resources and potential human health risks in the coal mining areas of Ib valley coalfield. In this perspective, a total of one hundred and two mine water and groundwater samples were collected from different locations. The water samples were analysed for some selected heavy metals i.e. Mn, Cu, Pb, Zn, Ni, Co, As, Se, Al, Sr, Ba, Cd, Cr, V and Fe using ICP-MS. In addition, pH and SO42− concentration were also measured following APHA procedure. The water pH in the Ib valley coalfields ranged from 3.26 to 8.18 for mine water and 5.23 to 8.52 for groundwater, indicating acidic to alkaline nature of water. Mn in mine water and Zn in groundwater environment were observed as the most dominant metals. The water hazard index (WHI) reflects that around 80% of mine water are non-toxic (WHI<5), 5% slightly toxic (5<WHI>10) and 15% extremely toxic (WHI>15). Relatively high pH and low concentration of dissolved metals and SO42− in groundwater as compared to mine water indicate lesser impact of mining activities. The calculated drinking water quality index (DWQI) suggests that Mn, Al, Ni and Fe in mine water and Mn, Fe, Ni and Pb in groundwater were the major objectionable metals which caused the water quality deterioration for drinking uses. Further, the non-carcinogenic health risk assessment for adult male, female and child populations identifies Co, Mn, Ni as the key elements making the water hazardous for human health. Comparatively higher ratio of ingestion rate and body weight in child population might be causing higher health risks in child population as compared to adult male and adult female population.