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Interior-point or barrier methods handle nonlinear programs by sequentially solving barrier subprograms with a decreasing sequence of barrier parameters. The specific barrier update rule strongly influences the theoretical convergence properties as well as the practical efficiency. While many global and local convergence analyses consider a monotone update that decreases the barrier parameter for every approximately solved subprogram, computational studies show a superior performance of more adaptive strategies. In this paper we interpret the adaptive barrier update as a reinforcement learning task. A deep Q-learning agent is trained by both imitation and random action selection. Numerical results based on an implementation within the nonlinear programming solver WORHP show that the agent successfully learns to steer the barrier parameter and additionally improves WORHP’s performance on the CUTEst test set.

PurposeThe incidences of atopic conditions (allergies, asthma, or eczema) and glioma vary by ethnicity. Atopic conditions are inversely associated with gliomas. We conducted a pooled multisite study investigating the associations of atopic conditions with glioma in different race/ethnicity groups.MethodsUsing glioma cases and healthy controls, unconditional logistic regression was conducted to assess the associations of atopic conditions with glioma separately in white, black, Asian, and Hispanic subpopulations. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated.ResultsGlioblastoma multiforme cases were less likely than controls to report a history of atopic conditions in whites (OR = 0.46, [95% CI, 0.38-0.54]) and Asians (OR = 0.27, [95% CI, 0.10-0.73]). The same trend was seen when looking at glioma cases of all histologies. An inverse association was not seen in blacks for glioblastoma multiforme or all histologies combined.ConclusionsThe inverse association between glioma and atopic conditions may vary by ethnicity due to a difference in the biology of atopic conditions in different ethnicities but may be due to chance because of the limitations of small nonwhite sample sizes.

Additive forging is a newly developed method to manufacture heavy forgings by using multilayer hot-compression bonding. However, the relationship between surface cleaning and bonding performance of bonded samples in the additive forging process is unclear. This paper studies the effect of surface cleaning on interface bonding performance for the first time. A new characterization method of surface cleanliness consisting of water contact angles, relative fluorescence units, and optical observation was proposed to characterize the cleaning effect. The micromorphologies and tensile properties were used to evaluate interface bonding performance. Elemental analysis and morphological analysis were used to infer the hindrance mechanism of contaminants. The results show that the new characterization method can effectively characterize the surface cleanliness of substrates. Moreover, the interfacial bonding performance results indicate that surface cleaning had a great influence on the bonding performance for 316H stainless steel joints manufactured by additive forging. Finally, the hindrance mechanisms of particles, chips, and oil contaminants were attributed to the hindrance effect in a radial direction, along the interface direction, and perpendicular to the interface direction respectively. This research builds a relationship between surface cleaning and bonding performance, which helps achieve high-performance manufacturing of heavy forgings.

Back Grinding of Wafer with Outer Rim (BGWOR) is a novel method for carrier-less thinning of silicon wafers. Silicon wafers are widely used in integrated circuits (ICs). The topography of the wafer will not only directly affect the efficiency of subsequent processing of semiconductor devices, but correspondingly affect the performance and life of these devices. However, there are few studies on the shape of the ground wafer in BGWOR. In this paper, the mathematical model of the wafer topography in BGWOR was developed. With this model, the radial thickness and total thickness variation (TTV) of a wafer under different parameters, including inclination angles and radii of grinding wheel for dressing chuck, were simulated by MATLAB. Inclination angles and radii of grinding wheels for the dressing chuck had a great influence on the radial thickness and TTV of a wafer in the BGWOR. Lastly, the pilot experiments were conducted to validate the theoretical model of grinding topography and TTV of the wafer in BGWOR. To enhance the flatness of the ground wafer, it is essential to control the shape of the dressing chuck. The research results are helpful to the optimization of the dressing process of the chuck in the BGWOR.

Transmission of arthropod-borne viruses (arboviruses) are an emerging global health threat in the last few decades. One important arbovirus family is the Togaviridae, including the species Sindbis virus within the genus Alphavirus. Sindbis virus (SINV) is transmitted by mosquitoes, but available data about the role of different mosquito species as potent vectors for SINV are scarce. Therefore, we investigated seven mosquito species, collected from the field in Germany (Ae. koreicus, Ae. geniculatus, Ae. sticticus, Cx. torrentium, Cx. pipiens biotype pipiens) as well as lab strains (Ae. albopictus, Cx. pipiens biotype molestus, Cx. quinquefasciatus), for their vector competence for SINV. Analysis was performed via salivation assay and saliva was titrated to calculate the amount of infectious virus particles per saliva sample. All Culex and Aedes species were able to transmit SINV. Transmission could be detected at all four investigated temperature profiles (of 18 ± 5 °C, 21 ± 5 °C, 24 ± 5 °C or 27 ± 5 °C), and no temperature dependency could be observed. The concentration of infectious virus particles per saliva sample was in the same range for all species, which may suggest that all investigated mosquito species are able to transmit SINV in Germany.

Polyetheretherketone (PEEK) is a promising thermo-plastic polymer material due to its excellent mechanical properties. To further improve the mechanical properties of PEEK, different kinds of short fibers are added into the PEEK matrix. The grinding machinability of short-fiber-reinforced PEEK varies with the effect of fiber type and content. Therefore, it is crucial to investigate the surface quality and removal mechanism of fiber-reinforced PEEK in ultra-precision grinding. In this paper, different fiber types and mass fractions of short-fiber-reinforced PEEK, including carbon-fiber-reinforced PEEK (CF/PEEK) and glass-fiber-reinforced PEEK (GF/PEEK), are employed. The grinding machinability of short-fiber-reinforced PEEK was investigated using grinding experiments with grinding wheels of different grit sizes. The effects of the fiber type and mass fraction on the surface quality and removal mechanism during grinding were discussed. The results showed that the brittle–ductile transition depth of carbon fiber was much larger than that of glass fiber, so it was easier to achieve ductile removal in grinding with the carbon fiber. Therefore, the ground surface roughness of CF/PEEK was smaller than that of GF/PEEK under the same grinding conditions. With the increase in carbon fiber mass fraction, the ground surface roughness of CF/PEEK decreased due to the higher hardness. The brittle–ductile transition depth of glass fiber was small, and it was easy to achieve brittle removal when grinding. When the glass fiber removal mode was brittle removal, the GF/PEEK surface roughness increased with the increase in glass fiber content.

It is evident that all the countries surrounding Ghana have experienced epidemics of key arboviruses of medical importance, such as the recent dengue fever epidemic in Burkina Faso. Therefore, Ghana is considered a ripe zone for epidemics of arboviruses, mainly dengue. Surprisingly, Ghana never experienced the propounded deadly dengue epidemic. Indeed, it is mysterious because the mosquito vectors capable of transmitting the dengue virus, such as Aedes aegypti, were identified in Ghana through entomological investigations. Additionally, cases may be missed, as the diagnostic and surveillance capacities of the country are weak. Therefore, we review the arbovirus situation and outline probable reasons for the epidemic mystery in the country. Most of the recorded cases of arbovirus infections were usually investigated via serology by detecting IgM and IgG immunoglobulins in clinical samples, which is indicative of prior exposure but not an active case. This led to the identification of yellow fever virus and dengue virus as the main circulating arboviruses among the Ghanaian population. However, major yellow fever epidemics were reported for over a decade. It is important to note that the reviewed arboviruses were not frequently detected in the vectors. The data highlight the necessity of strengthening the diagnostics and the need for continuous arbovirus and vector surveillance to provide an early warning system for future arbovirus epidemics.

A doença de Charcot-Marie-Tooth (CMT) é uma polineuropatia motora, sensitiva, hereditária e de predomínio distal. Os membros inferiores são os mais afetados e, ocasionalmente, há comprometimento dos membros superiores. Este estudo descreve a presença de disfagia orofaríngea e a intervenção fonoaudiológica em uma paciente de 58 anos com diagnóstico de CMT, encaminhada à avaliação fonoaudiológica devido a queixas na deglutição. Na avaliação inicial identificaram-se alterações, tanto de caráter estrutural quanto funcional, que resultaram em uma disfagia orofaríngea leve. Também se utilizou o Questionário de Qualidade de Vida na Disfagia para identificar o impacto na qualidade de vida da paciente. Após um mês de acompanhamento observou-se melhora dos sintomas e aumento do conforto e segurança ao deglutir.

Abstract Background The relationship between oral microbiota and IE (infective endocarditis) is well established. Opportunistic pathogens in normal oral flora enter the bloodstream through daily oral cleaning or invasive dental procedures, leading to the occurrence of infective endocarditis. An in vitro iron-deficient condition leads to a drastic community shift in oral microbiota with increasing proportions of taxa related to infective endocarditis. To investigate the relationship among insufficient iron supply, oral microbiota and the risk of IE and to conduct a population amplification study, iron-deficiency anaemia is used as an in vivo model. Methods This cross-sectional study enrolled 24 primary iron-deficiency anemia (IDA) patients from 2015.6 to 2016.6 from the hematology department of West China Hospital, Sichuan University, and 24 healthy controls. High-throughput sequencing compared the dental plaque microbiota of 24 IDA (iron-deficiency anaemia) patients and 24 healthy controls. Results Sequences were classified into 12 phyla, 28 classes, 50 orders, 161 genera and 497 OTUs (the IDA and control groups shared the same 384 OTUs). Iron deficiency leads to lower internal diversity in the oral flora. The abundances of genera Corynebacterium, Neisseria, Cardiobacterium, Capnocytophaga, and Aggregatibacter were significantly higher in healthy controls, while genera Lactococcus, Enterococcus, Lactobacillus, Pseudomonas and Moraxella showed higher proportions in the IDA group (P

Abstract Background The analysis of large mosquito samples is expensive and time-consuming, delaying the efficient timing of vector control measurements. Processing a fraction of a sample using a subsampling method can significantly reduce the processing effort. However, a comprehensive evaluation of the reliability of different subsampling methods is missing. Methods A total of 23 large mosquito samples (397–4713 specimens per sample) were compared in order to evaluate five subsampling methods for the estimation of the number of specimens and species: area, volume, weight, selection of 200 random specimens and analyses with an image processing software. Each sample was distributed over a grid paper (21.0 × 29.7 cm; 25 grid cells of 4.2 × 5.9 cm) with 200 randomly distributed points. After taking pictures, mosquito specimens closest to each of the 200 points on the paper were selected. All mosquitoes per grid cell were identified by morphology and transferred to scaled tubes to estimate the volume. Finally, the fresh and dry weights were determined. Results The estimated number of specimens and species did not differ between the area-, volume- and weight-based method. Subsampling 20% of the sample gave an error rate of approximately 12% for the number of specimens, 6% for the proportion of the most abundant species and between 6–40% for the number of species per sample. The error for the estimated number of specimens using the picture processing software ImageJ gave a similar error rate when analyzing 15–20% of the total sample. By using 200 randomly selected specimens it was possible to give a precise estimation of the proportion of the most abundant species (r = 0.97, P

In the electrochemical mechanical polishing (ECMP) of copper, hydroxyethylidene diphosphonic acid (HEDP) can work with other water treatment agents to suppress electrolysis and smooth the metal surface. According to Faraday's law, a conventional operating potential lower than 4 V vs. SCE limits the material removal rate (MRR). To solve this problem, potentiodynamic corrosion, potentiostatic corrosion and ECMP experiments were conducted at higher potentials to study the feasibility of the process. The results show that at 6 V vs. SCE, the roughness of a copper wafer was improved, with a MRR of about 0.9 μm·min−1, higher than that obtained at the conventional potential. A sample of the barrier film on the copper surface was collected and analyzed by energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR) and mass spectrometry to investigate the reaction mechanism. It is shown that the copper ions ionized from the working electrode (WE) react with two HEDP molecules to form the coordination compound [CuL2]6−, then K+ combines with [CuL2]6− to produce the coordination compound [KCuL2]5−. Keywords: Hydroxyethylidene diphosphonic acid, Electrochemical mechanical polishing, Copper, Reaction mechanism

Bearings-only tracking is a continuous-discrete system, whose state of motion is in the continuous-time domain and the measurement is in the discrete-time domain. The unpredicted approximation errors are inevitable due to integration, discretization, and linearization of continuous model in many filtering methods. The adaptive covariance feedback framework is proposed for solving this kind of problem, in which the posterior covariance sequence is proved theoretically to be useful for prior covariance updating. In this framework, the covariance feedback framework is integrated with the continuous-discrete cubature Kalman filtering, and Chebyshev distance is applied to judge the proper condition for the start-up of the feedback channel. The numerical results illustrate the proposed method’s superior performance in accuracy and computational efficiency.

Anopheles algeriensis Theobald, 1903, considered a competent vector of Plasmodium parasites, is a mosquito species widely distributed in the Mediterranean area but rare in Northern and Central Europe. The disappearance of its suitable breeding sites in Italy is having a detrimental effect on the occurrence of this species once common along the Southern coasts and on the islands. Recently, molecular investigations have renewed interest in this species, highlighting a genetic heterogeneity among European populations. In this study, An. algeriensis populations from Italy, Germany, Romania, and Sweden were analyzed by molecular typing of the intergenic transcribed spacer 2 (ITS2). The mitochondrial cytochrome c oxidase subunit I (COI) was also analyzed from specimens collected in Southern Italy. With the aim of investigating the population structure of this species, the obtained data were compared to all publicly available ITS2 and COI sequences of An. algeriensis, adding specimens from Spain and Portugal. The analyses of both markers indicate a split between Iberian populations (Spain for ITS2 and Spain/Portugal for COI) and those from the rest of Europe, revealing two cryptic species. The analysis of the COI barcode revealed a third clade representing a cryptic species present in Danube Delta (Romania). The high levels of genetic divergence among the clades of An. algeriensis indicate that this taxon represents a species complex, potentially harboring several distinct cryptic species.

The model of bearings-only tracking is generally described by discrete–discrete filtering systems. Discrete robust methods are also frequently used to address measurement uncertainty problems in bearings-only tracking. The recently popular continuous–discrete filtering system considers the state model of the target to be continuous in time, and is more suitable for bearings-only tracking because of its higher mathematical solution accuracy. However, the sufficient evaluation of robust methods in continuous–discrete systems is not available. In addition, in the different continuous–discrete measurement environments, the choice of a robust algorithm also needs to be discussed. To fill this gap, this paper firstly establishes the continuous–discrete target tracking model, and then evaluates the performance of proposed robust square-root continuous–discrete cubature Kalman filter algorithms in the measurement of uncertainty problems. From the simulation results, the robust square-root continuous–discrete maximum correntropy cubature Kalman filter algorithm and the variational Bayesian square-root continuous–discrete cubature Kalman filter algorithm have better environmental adaptability, which provides a promising means for solving continuous–discrete robust problems.

Silicon carbide (SiC) is a promising semiconductor material for making high-performance power electronics with higher withstand voltage and lower loss. The development of cost-effective machining technology for fabricating SiC wafers requires a complete understanding of the deformation and removal mechanism. In this study, molecular dynamics (MD) simulations were carried out to investigate the origins of the differences in elastic–plastic deformation characteristics of the SiC polytypes, including 3C-SiC, 4H-SiC and 6H-SiC, during nanoindentation. The atomic structures, pair correlation function and dislocation distribution during nanoindentation were extracted and analyzed. The main factors that cause elastic–plastic deformation have been revealed. The simulation results show that the deformation mechanisms of SiC polytypes are all dominated by amorphous phase transformation and dislocation behaviors. Most of the amorphous atoms recovered after completed unload. Dislocation analysis shows that the dislocations of 3C-SiC are mainly perfect dislocations during loading, while the perfect dislocations in 4H-SiC and 6H-SiC are relatively few. In addition, 4H-SiC also formed two types of stacking faults.

Background: Cleft palate (CP) patients have a higher prevalence of oral and respiratory tract bacterial infections than the general population. Nevertheless, characteristics of bacterial differences induced by CP-related anatomical heterogeneity are unknown. Methods: In this study, we systematically described the characteristics of bacteria in the oral and nasal niches in healthy children, CP children, healthy adolescents, CP adolescents, and postoperative adolescents by 454-pyrosequencing technology (V3–V6) to determine bacterial differences induced by CP. Results: Due to the CP-induced variations in spatial structure, the early establishment of microecology in CP children was different from that in healthy children. Nasal bacterial composition showed greater changes than in the saliva. Moreover, such discrepancy also appeared in CP and postoperative adolescents who had even undergone surgery > 10 years previously. Interestingly, we found by Lefse analysis that part of bacterial biomarkers in the nasal cavity of CP subjects was common oral flora, suggesting bacterial translocation between the oral and nasal niches. Therefore, we defined the oral–nasal translocation bacteria as O-N bac. By comparing multiple groups, we took the intersection sets of O-N bacs selected from CP children, CP adolescents, and postoperative adolescents as TS O-N bacs with time–character, including Streptococcus, Gemella, Alloprevotella, Neisseria, Rothia, Actinomyces, and Veillonella. These bacteria were at the core of the nasal bacterial network in CP subjects, and some were related to infectious diseases. Conclusions: CP would lead to significant and long-term differences in oral and nasal flora. TS O-N bacs migrating from the oral to the nasal might be the key stone causing nasal flora dysbiosis in the CP patients.

For a number of years chronic kidney disease (CKD) has been listed in the group of lifestyle diseases, such as obesity, diabetes, cardiovascular disease and hypertension. It is estimated that in Poland more than 4 million people may suffer from various stages of CKD. Chronic kidney disease may also be a consequence of all the other civilization diseases. At the same time it is worth noting that nephrological problems are increasingly being taken into account in modern medical certification. The aim of this work is, among other things, to improve safe access to the labor for patients with kidney diseases. In the legislation existing in our country since 2014 it is stated that chronic renal failure is a potential health contraindication to driving. Also in the annex to the Regulation of the Minister of Health dated 9 December 2015 on health conditions required for seafarers to work on a seagoing ship, it is said that ICD-10 codes (International Classification of Diseases) corresponding to acute and chronic renal failure (N17–N19) should be taken into account when qualifying employees to work at sea. Med Pr 2018;69(1):67–75

Abstract Background Different mosquito-borne pathogens are circulating in Iran including Sindbis virus, West Nile virus, filarioid worms and malaria parasites. However, the local transmission cycles of these pathogenic agents are poorly understood, especially because ecological data on vector species are scarce and there is limited knowledge about the host range; this understanding could help to direct species-specific vector control measurements or to prioritize research. Methods In the summers of 2015 and 2016, blood-fed mosquitoes were collected at 13 trapping sites on the coast of the Caspian Sea in northern Iran and at an additional trapping site in western Iran. Mosquitoes were generally collected with either a Biogents Sentinel trap or a Heavy Duty Encephalitis Vector Survey trap installed outside. A handheld aspirator was used at the trapping site in western Iran, in addition to a few samplings around the other trapping sites. On average, eight trapping periods were conducted per trapping site. The sources of blood meals were identified using a DNA barcoding approach targeting the cytochrome b or 16S rRNA gene fragment. Results The source of blood meals for 580 blood-fed mosquito specimens of 20 different taxa were determined, resulting in the identification of 13 different host species (9 mammals including humans, 3 birds and 1 reptile), whereby no mixed blood meals were detected. Five mosquito species represented more than 85.8% of all collected blood-fed specimens: Culex pipiens pipiens form pipiens (305 specimens, 55.7% of all mosquito specimens), Cx. theileri (60, 10.9%), Cx. sitiens (51, 9.3%), Cx. perexiguus (29, 5.3%) and Anopheles superpictus (25, 4.6%). The most commonly detected hosts of the four most abundant mosquito species were humans (Homo sapiens; 224 mosquito specimens, 40.9% of all mosquito specimens), cattle (Bos taurus; 171, 31.2%) and ducks (Anas spp.; 75, 13.7%). These four mosquito species had similar host-feeding patterns. The only exceptions were a relatively high proportion of birds for Cx. pipiens pipiens f. pipiens (23.2% of detected blood meal sources) and a high proportion of non-human mammals for Cx. theileri (73.4%). Trapping month, surrounding area, or trapping method had no statistically significant impact on the observed host-feeding patterns of Cx. pipiens pipiens f. pipiens. Conclusions Due to the diverse and overlapping host-feeding patterns, several mosquito species must be considered as potential enzootic and bridge vectors for diverse mosquito-borne pathogens in Iran. Most species can potentially transmit pathogens between mammals as well as between mammals and birds, which might be the result of a similar host selection or a high dependence on the host availability.

Objectives To comprehensively map the existing evidence assessing the impact of travel-related control measures for containment of the SARS-CoV-2/COVID-19 pandemic.Design Rapid evidence map.Data sources MEDLINE, Embase and Web of Science, and COVID-19 specific databases offered by the US Centers for Disease Control and Prevention and the WHO.Eligibility criteria We included studies in human populations susceptible to SARS-CoV-2/COVID-19, SARS-CoV-1/severe acute respiratory syndrome, Middle East respiratory syndrome coronavirus/Middle East respiratory syndrome or influenza. Interventions of interest were travel-related control measures affecting travel across national or subnational borders. Outcomes of interest included infectious disease, screening, other health, economic and social outcomes. We considered all empirical studies that quantitatively evaluate impact available in Armenian, English, French, German, Italian and Russian based on the team’s language capacities.Data extraction and synthesis We extracted data from included studies in a standardised manner and mapped them to a priori and (one) post hoc defined categories.Results We included 122 studies assessing travel-related control measures. These studies were undertaken across the globe, most in the Western Pacific region (n=71). A large proportion of studies focused on COVID-19 (n=59), but a number of studies also examined SARS, MERS and influenza. We identified studies on border closures (n=3), entry/exit screening (n=31), travel-related quarantine (n=6), travel bans (n=8) and travel restrictions (n=25). Many addressed a bundle of travel-related control measures (n=49). Most studies assessed infectious disease (n=98) and/or screening-related (n=25) outcomes; we found only limited evidence on economic and social outcomes. Studies applied numerous methods, both inferential and descriptive in nature, ranging from simple observational methods to complex modelling techniques.Conclusions We identified a heterogeneous and complex evidence base on travel-related control measures. While this map is not sufficient to assess the effectiveness of different measures, it outlines aspects regarding interventions and outcomes, as well as study methodology and reporting that could inform future research and evidence synthesis.

Building information modeling (BIM) is an emerging technology that can effectively solve the problems of information dispersion, complex personnel management, and lack of construction supervision, which often occur during the construction of tunnel engineering. Taking the construction of Haicang Tunnel in Xiamen, China as a case study, the utilization of BIM technology in the design stage, the construction simulation and operation are demonstrated during the full-life cycle of the project. During the construction of Haicang Tunnel, the technologies of BIM 3D, BIM 4D, BIM 5D, and Cloud Platform are used to make the construction process controllable and to facilitate the implementation and deployment of construction plans. BIM 3D is a visualization method to show the detailed model in the construction. The design is optimized by the navigation collision function of BIM 3D. BIM 4D adds the time schedule into BIM 3D model to show the construction schedule. BIM 5D adds the cost into BIM 4D model to show the construction consumption. The methods of BIM 4D and BIM 5D can assist the engineering management in allocating resources and funds in the project. Cloud Platform is used to effectively implement information management.

BackgroundCirculating levels of the endogenous inhibitor of nitric oxide synthase, asymmetric dimethylarginine (ADMA), are positively associated with the prevalence of metabolic syndrome (MetS) in cross-sectional investigations. It is unclear if circulating ADMA and other methylarginines are associated with incident MetS prospectively.MethodsWe related circulating ADMA, symmetric dimethylarginine (SDMA), L-arginine (ARG) concentrations (measured with a validated tandem mass spectrometry assay) and the ARG/ADMA ratio to MetS and its components in 2914 (cross-sectional analysis, logistic regression; mean age 58 years, 55% women) and 1656 (prospective analysis, Cox regression; mean age 56 years, 59% women) individuals from the Framingham Offspring Study who attended a routine examination.ResultsAdjusting for age, sex, smoking, and eGFR, we observed significant associations of ADMA (direct) and ARG/ADMA (inverse) with odds of MetS (N = 1461 prevalent cases; Odds Ratio [OR] per SD increment 1.13, 95%CI 1.04-1.22; and 0.89, 95%CI 0.82-0.97 for ADMA and ARG/ADMA, respectively). Upon further adjustment for waist circumference, systolic and diastolic blood pressure, glucose, high-density lipoprotein cholesterol, and triglycerides, we observed a positive relation between SDMA and MetS (OR per SD increment 1.15, 95% CI 1.01-1.30) but the other associations were rendered statistically non-significant. We did not observe statistically significant associations between any of the methylarginines and the risk of new-onset MetS (752 incident events) over a median follow-up of 11 years.ConclusionIt is unclear whether dimethylarginines play an important role in the incidence of cardiometabolic risk in the community, notwithstanding cross-sectional associations. Further studies of larger samples are needed to replicate our findings.

The emergence of a highly transmissible and a more pathogenic B.1.617.2 (delta) variant of SARS-CoV-2 has brought concern over COVID-19 vaccine efficacy and the increased risk of severe breakthrough infections. The objective of this study was to assess the frequency and the clinical characteristics of severe breakthrough COVID-19 cases recorded in 10 Polish healthcare units between 1 June and 31 December 2021, a period during which a rapid surge in the share of B.1.617.2 infections was seen, while a significant number of populations were already fully vaccinated. Overall, 723 individuals who completed the initial vaccination regime (fully vaccinated group) and an additional 18 who received a booster dose were identified—together, they represented 20.8% of all the COVID-19 patients hospitalized during the same period in the same healthcare institutions (0.5% in the case of a group that received a booster dose). Although laboratory and clinical parameters did not differ between both groups, patients who received a booster tended to have lower CRP, IL-6, PCT, and d-dimer levels and they required oxygen therapy less frequently. The most common early COVID-19 symptoms in the studied group were fatigue, cough, fever (>38 °C), and dyspnea. Individuals with no detectable anti-spike IgG antibodies constituted 13%; the odds of being a humoral non-responder to the vaccine were increased in patients aged >70 years. Fully vaccinated patients hospitalized after more than 180 days from the last vaccine dose were significantly older and they were predominantly represented by individuals over 70 years and with comorbidities, particularly cardiovascular disease. Contrary to mRNA vaccines, most patients vaccinated with adenoviral vector vaccines were infected within six months. A total of 102 fatal cases (14% of all deaths among vaccinated individuals; 0.7% in the case of a group that received a booster dose) were recorded, representing 17.6% of all the COVID-19 fatalities recorded in June–December 2021 in the considered healthcare units. The odds of death were significantly increased in men, individuals aged >70 years, patients with comorbidities, and those identified as humoral non-responders to vaccination; in fully vaccinated patients the odds were also increased when the second vaccine dose was given >180 days before the first COVID-19 symptoms. The mortality rate in immunocompromised subjects was 19%. The results indicate that compared to vaccinated individuals, severe COVID-19 and deaths in the unvaccinated group were significantly more prevalent during the B.1.617.2-dominated wave in Poland; and, it highlight the protective role of a booster dose, particularly for more vulnerable individuals.

The uptake transporter NaCT (gene symbol SLC13A5) is expressed in liver and brain and important for energy metabolism and brain development. Substrates include tricarboxylic acid cycle intermediates, e.g., citrate and succinate. To gain insights into the substrate spectrum of NaCT, we tested whether arginine and the cardioactive L-arginine metabolites asymmetric dimethylarginine (ADMA) and L-homoarginine are also transported by human and mouse NaCT/Nact. Using HEK293 cells overexpressing human or mouse NaCT/Nact we characterized these substances as substrates. Furthermore, inhibition studies were performed using the arginine derivative symmetric dimethylarginine (SDMA), the NaCT transport inhibitor BI01383298, and the prototypic substrate citrate. Arginine and the derivatives ADMA and L-homoarginine were identified as substrates of human and mouse NaCT. Transport of arginine and derivatives mediated by human and mouse NaCT were dose-dependently inhibited by SDMA. Whereas BI01383298 inhibited only human NaCT-mediated citrate uptake, it inhibits the uptake of arginine and derivatives mediated by both human NaCT and mouse Nact. In contrast, the prototypic substrate citrate inhibited the transport of arginine and derivatives mediated only by human NaCT. These results demonstrate a so far unknown link between NaCT/Nact and L-arginine and its cardiovascular important derivatives.

Proline-rich antimicrobial peptides (PrAMPs) are promising candidates to treat bacterial infections. The designer peptide ARV-1502 exhibits strong antimicrobial effects against Enterobacteriaceae both in vitro and in vivo. Since the inhibitory effects of ARV-1502 reported for the 70 kDa heat-shock protein DnaK do not fully explain the antimicrobial activity of its 176 substituted analogs, we further studied their effect on the bacterial 70S ribosome of Escherichia coli, a known target of PrAMPs. ARV-1502 analogues, substituted in positions 3, 4, and 8 to 12 (underlined) of the binding motif D3KPRPYLPRP12 with aspartic acid, lysine, serine, phenylalanine or leucine, were tested in a competitive fluorescence polarization (FP) binding screening assay using 5(6)-carboxyfluorescein-labeled (Cf-) ARV-1502 and the 70S ribosome isolated from E. coli BW25113. While their effect on ribosomal protein expression was studied for green fluorescent protein (GFP) in a cell-free expression system (in vitro translation), the importance of known PrAMP transporters SbmA and MdtM was investigated using E. coli BW25113 and the corresponding knockout mutants. The dissociation constant (Kd) of 201 ± 16 nmol/L obtained for Cf-ARV-1502 suggests strong binding to the E. coli 70S ribosome. An inhibitory binding assay indicated that the binding site overlaps with those of other PrAMPs including Onc112 and pyrrhocoricin as well as the non-peptidic antibiotics erythromycin and chloramphenicol. All these drugs and drug candidates bind to the exit-tunnel of the 70S ribosome. Substitutions of the C-terminal fragment of the binding motif YLPRP reduced binding. At the same time, inhibition of GFP expression increased with net peptide charge. Interestingly, the MIC values of wild-type and ΔsbmA and ΔmdtM knockout mutants indicated that substitutions in the ribosomal binding motif altered also the bacterial uptake, which was generally improved by incorporation of hydrophobic residues. In conclusion, most substituted ARV-1502 analogs bound weaker to the 70S ribosome than ARV-1502 underlining the importance of the YLPRP binding motif. The weaker ribosomal binding correlated well with decreased antimicrobial activity in vitro. Substituted ARV-1502 analogs with a higher level of hydrophobicity or positive net charge improved the ribosome binding, inhibition of translation, and bacterial uptake.

Polyetheretherketone (PEEK) is a novel polymer material with excellent material properties. The hardness and strength of PEEK can be further improved by introducing fiber reinforcements to meet the high-performance index of the aerospace industry. The machinability will be influenced when the material properties change. Therefore, it is crucial to investigate the influence of material properties of the fiber-reinforced PEEK on machinability. In this paper, the main materials include pure PEEK, short carbon-fiber-reinforced PEEK (CF/PEEK), and short glass-fiber-reinforced PEEK (GF/PEEK). The effects of the fiber type and mass fraction on the tensile strength, hardness, and elastic modulus of materials were discussed using the tensile test and nanoindentation experiments. Furthermore, the fiber-reinforced PEEK lapping machinability was investigated using lapping experiments with abrasive papers of different mesh sizes. The results showed that the hardness and elastic modulus of PEEK could be improved with fiber mass fraction, and the tensile strength of CF/PEEK can be improved compared with that of GF/PEEK. In terms of lapping ability, the material removal rates of the fiber-reinforced materials were found to be lower than the pure PEEK due to the higher hardness of the fiber. During the lapping process, the material removal methods mainly included the ductile deformation or desquamation of reinforcing fiber and ductile removal of the PEEK matrix. The lapped surface roughness of PEEK material can be improved by fiber reinforcement.

The aim of this study was to analyze the waning of anti-spike (S) antibodies after mRNA vaccination against COVID-19 in maintenance dialysis patients, and to assess the safety and effectiveness of the complementary third dose. This was a prospective, longitudinal study in which we analyzed the kinetics of antibodies up to six months after a two-dose vaccination (first protocol) in infection-naïve dialysis patients (IN-Ds), previously infected dialysis patients (PI-Ds) and subjects without chronic kidney disease (the controls), as well as their humoral response to the third dose of the same mRNA vaccine (second protocol). The respective reduction in antibody titer after 3 and 6 months by 82.9% and 93.03% in IN-Ds (n = 109), 73.4% and 93.36% in PI-Ds (n = 32) and 75.5% and 88.8% in the controls (n = 20) was demonstrated. Consequently, a protective antibody titer above 141 BAU/mL was found in only 47.7% and 23.8% of IN-Ds after 3 and 6 months, respectively. After the third vaccine dose, a significant increase in antibody titer was observed in all groups, with increases by a factor of ×51.6 in IN-Ds, ×30.1 in the controls and ×8.4 in PI-Ds. The median antibody titer after the third dose differed significantly between groups, and was the highest in PI-Ds: PI-Ds, 9090 (3300–15,000) BAU/mL; the controls, 6945 (2130–11,800); IN-Ds, 3715 (1470–7325) (p < 0.001). In conclusion, we observed similar degrees of antibody waning in all patients. After 3 months, over half of the infection-naïve dialysis patients had a very low antibody titer, and almost twenty percent of them had no antibodies at all. The humoral response to the third dose was very good, raising their titer of antibodies to a higher level than those in the general population who have received the primary two-dose scheme. The results support the administration of a complementary third dose of the mRNA vaccine for dialysis patients as soon as possible.

Removing carbon deposition (CD) has always been a challenging problem. On the inner surface of a turbo shaft, CD is observed by scanning electron microscopy (SEM) to analyze its microstructure and composition, and its formation mechanism is analyzed by X-ray diffraction (XRD), infrared spectroscopy, and Raman spectroscopy. Considering the physical and chemical properties of deposited carbon, chemically assisted magnetic grinding (CAMG) is proposed and tested by a translational permanent magnet grinding device. By analyzing the removing mechanism of CAMG, response surface analysis is adopted to analyze the influence law of surface roughness based on the interactions between pairs of the three following parameters: the rotational speed of the rotating magnetic field, needle type, and grinding time. The optimal process parameters can be obtained with a rotational speed of the rotating magnetic field of 600 r/min, a needle type of Φ 1.0 × 5 mm, and a grinding time of 60 min. The surface quality of the workpiece processed by CAMG can be comprehensively appraised by observing the microstructure, calculating the carbon deposit removal ratio and testing the surface stress. Compared to single magnetic grinding, CAMG is more environmentally friendly and has a higher removal ratio and better surface quality with an obvious decrease in residual stress. By professional tests, the remaining deposited carbon is less than the specified value required by the technology, which satisfies the requirements of enterprises.

Mechanical drilling can change the microstructure of the regions near the hole wall, remarkably affecting the working performance of precision parts. The present work investigated the microstructural evolution in the regions from the drilled hole wall to the inner matrix of the soft magnetic 49Fe-49Co-2V alloy after the common drilling experiments were carried out. The microstructures and microhardness in different regions near the hole wall along the radial direction were characterized with OM, SEM, TEM, EBSD and Vickers Microhardness tester. The experimental results show that the nearest region to the hole wall is constituted of nano-sized refined grains. It exhibits a disordered BCC phase due to the rapid cooling from the high temperature during the drilling, different from the dual-phase of BCC and B2 of the matrix. The second-nearest region to the hole wall is distributed by a huge number of dislocations, leading to a maximum in microhardness. The microstructural evolution contributes to the variation of the microhardness, which increases firstly, reaches a maximum, and then decreases to the level of the matrix with the distance increasing from the hole wall. This variation tendency is discussed in light of both refined grain-boundary strengthening and dislocation strengthening mechanisms. Keywords: 49Fe-49Co-2V alloy, Drilling, Microstructural evolution, Microhardness, Strengthening mechanisms

The vulnerability of prospective credit consumers to over-committing their resources and the inherent dangers posed by credit advertising in particular necessitate the proper regulation of credit marketing. It is therefore not unsurprising that responsible marketing forms part of the responsible lending (and borrowing) measures of various jurisdictions – including South Africa and the Member States of the European Union – with the aim of preventing the extension of credit to consumers who cannot afford it. In this article the credit marketing laws that the South African, European (mainly in the Consumer Credit and Mortgage Credit Directives) and Belgian legislators have enacted are considered and compared, with a focus on the information to be included in advertising, prohibited advertising and prohibited marketing techniques. The ultimate aim is to determine whether South African law contains sufficient guarantees to protect consumers with respect to credit marketing and its consequences.

The vulnerability of prospective credit consumers to over-committing their resources and the inherent dangers posed by credit advertising in particular necessitate the proper regulation of credit marketing. It is therefore not unsurprising that responsible marketing forms part of the responsible lending (and borrowing) measures of various jurisdictions – including South Africa and the Member States of the European Union – with the aim of preventing the extension of credit to consumers who cannot afford it. In this article the credit marketing laws that the South African, European (mainly in the Consumer Credit and Mortgage Credit Directives) and Belgian legislators have enacted are considered and compared, with a focus on the information to be included in advertising, prohibited advertising and prohibited marketing techniques. The ultimate aim is to determine whether South African law contains sufficient guarantees to protect consumers with respect to credit marketing and its consequences.