Contact Test Research Articles

Better communication with migrant communities during COVID-19 pandemic:a portuguese experience

Abstract Odemira, in the southeast litoral of Portugal, has 33% of migrant citizens, mostly from Southeast Asia, going up to 50% counting transient citizens. Most of them do not speak English, making communication with health services difficult. They tend to live in overcrowded houses with unsanitary conditions. With the emergence of the COVID-19 pandemic, all the above resulted in high incidence and ineffective contact tracing (CT), testing and isolation by the public health teams. It was essential to develop strategies to manage and control outbreaks, and also to achieve health equity. Our experience can be useful for other countries in dealing with their multicultural communities. This intervention started in march 2020 and is still ongoing. The aims were to improve the accuracy of epidemiological surveys (ES) and CT, to more easily stop transmission, to develop the communication skills of health professionals and to improve migrant's healthcare access. For this, the focus was on digital written communication tools (Whatsapp, translation apps). It was created a toolkit to guide ES and CT tailored to the migrant population, with tips and best practices, and used translated information materials about preventive COVID-19 measures. Workshops were led with health professionals. It was stablished work with local NGOs, creating social media campaigns during crucial events (Holi holliday). As results. it was achieved a better ES output, more accurate CT and better transmission control, with noticeable differences between march 2020 and now. The relationship with this community improved, having better access to services and their needs met. Health professionals reported being more at ease dealing with these patients. Our experience shows it's possible to communicate effectively despite language and cultural barriers, that cultural knowledge is important in advancing public health goals and that multidisciplinary and intersectoral work is essential to effective interventions. Key messages This intervention allowed us to achieve a better output of epidemiological surveys, more accurate contact tracing and were more effective in breaking transmission chains and controlling outbreaks. It was achieved a better understanding and relationship with this community, with better ability to respond to their needs and promoting their access to healthcare.

8.M. Round table: The Why, the How, and the Tensions in the response of European SPHs to the 2020 COVID-19 pandemic

With its repeated waves of infection and a high death toll in countries all over the world, the COVID-19 pandemic places the public health (PH) discipline at the centre of public attention. Thus, it is a crucial ethical requirement to activate all available resources of PH knowledge and skills, nationally as well as internationally, in response to the pandemic. Universities, Schools and Departments of Public Health (SPHs) hold important resources in terms of theoretical and practical competences. In order that PH professionals will have the necessary competences to deliver the Essential Public Health Operations (EPHOs) to combat health threats, e.g. pandemics, the Association of Schools of Public Health in the European Region (ASPHER) has developed competency systems and lists for the PH workforce as well as for the academic knowledge and skills foundation of PH in its broadest sense. The membership of ASPHER thus represents a substantial resource of PH knowledge and skills, enabling the SPHs to play a critical role also in the COVID-19 pandemic. To develop the knowledge and skills resources further, ASPHER however set up a COVID-19 Task Force to describe and analyse the many-sided dynamic challenges, which the pandemic presents to society and thus to the role of PH institutions and professionals. Under normal circumstances, the central roles of the SPHs are teaching and research and, to a more limited extent, health communication to the public and giving advice to society's decision makers. The question however is, whether and to what extent these crucial resources actually are activated across the walls of the schools during the present pandemic. To throw light on this, the Task Force performed a survey on the actual, concrete role of ASPHER's members in the pandemic during 2020. Half (59) of the member SPHs responded. Eight out ten had engaged in both COVID-19 related teaching and communication to the public, and in COVID-19 related research as well as giving advice to national, regional and local decision makers. The target groups of teaching were PH students as well as students within other health disciplines. Health communication to the public was performed by use of a series of classic and modern media techniques. Both planned and published anti-COVID-19 research was reported. A large variation of subthemes was considered and employed within each of the four main themes, so that all ten Essential Public Health Operation (EPHO) main categories were represented. Consultancy was practiced in various international, national and local contexts and with effect on decision making. The main objective of the present panel discussion is to show and discuss, how European SPHs responded concretely to the COVID-19 pandemic through 2020, as shown in all main parts of their activities. Examples will be contact tracing (Dublin SPH), testing (Olomouc SPH), vaccination (Milan SR-SPH), training (Granada SPH), and development of mathematical simulation models (Copenhagen SPH).Speakers/Panelists Mary Codd University College Dublin, Dublin, Ireland Alena Petráková Faculty of Medicine and Dentistry, Palacky University Olomouc, Olomouc, Czechia Carlo Signorelli University Vita-Salute San Raffaele, Milan, Italy Alberto Fernández Ajuria Escuela Andaluza de Salud Pública, Granada, Spain Theis Lange Department of Public Health, University of Copenhagen, Copenhagen, Denmark Key messages Thinking out of the box: SPHs adjusted quickly to the demand shaped by the pandemic.This counts for education/training, communication with the public, research, and providing consultancy/advice to national, regional and local society leaders.

Limitation of Water-Soluble Tetrazolium Salt for the Cytocompatibility Evaluation of Zinc-Based Metals.

Zinc (Zn) and its alloys have been regarded as promising biodegradable metals. The standardized cytotoxicity evaluation is a mandatory step to screen the biocompatibility of novel Zn and its alloys. Nevertheless, the suitability of the tetrazolium-based assay in the direct contact test for some metallic biomaterials (i.e., magnesium and manganese) is questionable. In this study, our results demonstrate an obvious inconsistency between qualitative observation via fluorescence staining and quantitative assessment using water-soluble tetrazolium salt (CCK-8). Subsequent experiments revealed that Zn and pre-treated Zn can directly convert tetrazolium salts to formazan, falsifying the cytotoxicity results. Therefore, we conclude that the CCK-8 assay is not suitable for evaluating the cytotoxicity of biodegradable Zn-based metals in the direct contact test.

Chemical Characterization and Antioxidant, Antimicrobial, and Insecticidal Properties of Essential Oil from Mentha pulegium L.

The chemical composition and antibacterial, insecticidal, and antioxidant properties of the essential oil from Mentha pulegium L. (M. pulegium) growing in Morocco were investigated in this work. To achieve this goal, the oils were obtained by using hydrodistillation before being characterized by GC-MS. The antibacterial and antifungal activities were conducted against pathogenic strains using the disc diffusion and MICS bioassays. The insecticidal activity was carried out versus C. maculatus using contact and inhalation tests. The antioxidant activity was performed by using DPPH and total antioxidant capacity bioassays. The chemical analysis of the oil showed that 20 compounds were identified, which represented 98.91% of the total oil. In the oil, the main components detected were R-(+)-pulegone (76.35%), carvone (5.84%), dihydrocarvone (5.09%), and octanol-3 (2.25%). The essential oil has moderate-to-strong broad-spectrum antibacterial and antifungal properties; the results showed that B. subtilis was the most sensitive strain to M. pulegium oil, with the largest inhibition diameter (25 ± 0.33). For the antifungal activity, the results obtained indicated that Aspergillus niger was the most sensitive fungal strain to M. pulegium oil with an inhibition percentage up to 100%. Regarding the insecticidal activity, the inhalation test showed a high efficacy (100% mortality), and a lethal concentration of LC50 = 1.41 + 0.48 μL/L air was obtained after 24 hours of exposure. Moreover, the contact test showed that a total reduction in fertility and emergence was obtained with a dose of 20 μL/mL of acetone. Regarding the antioxidant activity, the sample concentration necessary to inhibit 50% of HE radicals (IC50) was 7.659 mg/mL (DPPH) and 583.066 57.05 mg EAA/g EO (TAC).

Experience from five Asia-Pacific countries during the first wave of the COVID-19 pandemic: Mitigation strategies and epidemiology outcomes

BackgroundWith no vaccines or specific treatments, non-pharmaceutical interventions are the only tools for controlling the human-to-human transmission of the COVID-19 disease, which appeared in Wuhan, China last December and has spread globally since. Here we describe and compare the first-wave mitigation strategies and epidemiology of five Asia-Pacific countries that responded rapidly to the epidemic. MethodsFrom January to April 2020, mitigation measures and epidemiological data for Singapore, South Korea, Japan, Taiwan, Hong Kong were screened from official local government websites and a review of investigational studies was conducted. Daily case reports and mitigation measures information were extracted. Epidemiological estimates were calculated and compared between countries. ResultsAll five countries combined measures, focusing on contact tracing, testing, isolation efforts and healthcare management. Epidemiological data varied temporally and geographically: incubation period ranged 3.9–7.1 days, effective reproduction number at time t (Rt) ranged 0.48–1.5, with intensive care admissions 1–3% of hospitalised patients, and case fatality rates were 0.1–3%. Extrinsic estimates to the virus were lower than global estimates. ConclusionImplemented mitigation strategies in these countries allowed a rapid and successful control or delay of the first COVID-19 pandemic wave. These are valuable examples to inform subsequent waves.

Enhancement of the bone-implant interface by applying a plasma-sprayed titanium coating on nanohydroxyapatite/polyamide66 implants in a rabbit model

Solid fusion at the bone-implant interface (BII) is considered one of the indicators of a satisfactory clinical outcome for spine surgery. Although the mechanical and physical properties of nanohydroxyapatite/polyamide66 (n-HA/PA66) offers many advantages, the results of long-term follow-up for BIIs remain limited. This study aimed to improve the BII of n-HA/PA66 by applying plasma-sprayed titanium (PST) and assessing the mechanical and histological properties. After the PST coating was applied to n-HA/PA66 implants, the coating had uneven, porous surfaces. The compression results were not significantly different between the two groups. The micro-CT results demonstrated that at 6 weeks and 12 weeks, the bone volume (BV), BV/tissue volume (TV) and trabecular number (Tb.N) values of the n-HA/PA66-PST group were significantly higher than those of the n-HA/PA66 group. The results of undecalcified bone slicing showed that more new bone appeared to form around n-HA/PA66-PST implant than around n-HA/PA66 implant. The bone-implant contact (BIC) and push-out test results of the n-HA/PA66-PST group were better than those of the n-HA/PA66 group. In conclusion, after PST coating, direct and additional new bone-to-implant bonding could be achieved, improving the BII of n-HA/PA66 implants. The n-HA/PA66-PST implants could be promising for repair purposes.

A numerical-experimental study of AISI 316L borided steels under cyclic contact loading

AISI 316L borided steels under cyclic contact loading were evaluated. Boriding was carried out by two powder-pack processes: the continuous and interrupted processes. Boriding processes were developed at 900 °C for 1 h (continuous process) and 4 h (interrupted process). A monolayer mainly formed by Fe 2 B was obtained by the interrupted boriding with a thickness of 6.09 ± 0.31 μm and a surface hardness of 22.3 ± 1.4 GPa. In contrast, a FeB-Fe 2 B bilayer was formed by the continuous boriding with a total thickness of 13.08 ± 0.39 μm and a surface hardness of 26.3 ± 2.1 GPa. Adhesion tests were developed, in which the monolayer showed better adhesion than that the bilayer. Cyclic contact tests were carried out by loading a ball on the borided steel surface. Circular cracks because of the applied critical load (monotonic load) were observed on the borided steel surface. Subcritical loads were applied to the borided steels, where cohesive damage was caused in the bilayer, whereas no damage was observed in the monolayer at low subcritical loads. In contrast, circular cracks were observed in both treatment conditions at high subcritical loads. In addition, the high percentage of the FeB phase caused a more severe damage upon the bilayer system. Additionally, the thinner thickness of the boride layer, as well as the presence of compressive residual stresses (−0.75 GPa) in the monolayer system, caused a decrease on the maximum principal stress (2.4 GPa at the highest applied load) caused by contact loading compared to bilayer system (5.2 GPa at the highest applied load). Therefore, the interrupted boriding (monolayer system) showed a better mechanical resistance under cyclic contact loads than the continuous boriding (bilayer system). • FeB-Fe 2 B and Fe 2 B layers were obtained by continuous and interrupted boriding. • The bilayer system showed more severe damage under cyclic contact loads. • The plastic deformation of the substrate decreased the damage in the monolayer system.

Toxicity and repellent activities of Thymus pallescens and Cymbopogon citratus essential oils against Sitophylus granarius

This study evaluated the toxicity and repellent activities of essential oils (EOs) against Sitophilus granarius (Linnaeus, 1758), both in vitro and in vivo conditions. The EOs obtained from Thymus pallescens Noë. (Lamiaceae) and Cymbopogon citratus Stapf. (Poaceae) were analyzed by GC-MS, and revealed that carvacrol (56.64%) and geraniol (20.8%) as the respective major components. T. pallescens EO was found to be a more effective toxicant, with LC<sub>50</sub> and LC<sub>90</sub> values of 9.3 and 34.6 µL/mL, respectively, in the contact test vs 8.2 and 25.3 µL/mL in the fumigation test. T. pallescens EO showed also a stronger repellent effect with values ranging from 83.4% to 100%. In the in vivo test, the survival probability decreased from 99.9 to 2.48% among insects exposed to T. pallescens EO. These data demonstrated that EOs could be considered effective alternatives to chemical insecticides, providing pest control for stored products in an ecologically sustainable manner.

Evaluation of the Efficacy of Some Plant Oil Extracts in the Management of Tribolium castaneum (Herbst)

Four-way olfactometer was used to evaluate Laboratory repellency activities of Azadirachta indica, Jatropha curcas and Dennitia tripetala oil extracts on Tribolium castaneum at 10µl of each oil. Each arm of the olfactometer served as treatment arm with the 3 arms accommodating the 3 test substances, respectively and the 4th arm as control. Various concentrations (1, 2 and 3% V/V) of the essential oils were evaluated for fumigant and contact toxicity against T. castaneum at 8, 16 and 24 hours durations. The results obtained showed that T. castaneum spent significantly (p<0.05) more time (min) in the control arm than the 3 arms accommodating the essential oils. Similarly, significantly (p<0.05) more number of entries were made by the insect into the control arm compared with the test arms. The application of the essential oils significantly (p<0.05) caused higher mortality at 8, 16 and 24hrs than the control for both fumigant and contact tests. The mortality of the T. castaneum increased with increase in the concentration of the essential oils. The 3% concentrations of the oil extracts significantly caused the highest mortality, 67.23±8.72, 69.22± 18.74 and 79.55±9.29% by A. indica, D. tripetala and J. curcas, respectively after 24 hours application in fumigant test. The result also indicated that the contact application of A. indica, D. tripetala and J. curcas at 3% concentrations resulted in 63.07±6.55, 70.10±2.51 and 67.4±4.06% mortality of T. castaneum, respectively. The results suggest that the oil extracts from A. indica, J. curcas and D. tripetala can be used for effective management of T. castaneum infesting stored products.

Time of Test Periods Influence the Behavioral Responses of Anopheles minimus and Anopheles dirus (Diptera: Culicidae) to DEET.

Simple SummaryThe influence of environmental and physiological factors on various aspects of normal mosquito behavior is unclear. The efficacy of repellents against mosquitoes depends on the vector species as well as the concentration and formulation of the repellent. In this study, we observed the behavioral responses of two night-biting malaria vectors in Thailand, Anopheles minimus and Anopheles dirus, during daytime and nighttime. We demonstrated that time of observation has a considerable impact on behavioral responses for both species. When optimizing an excito-repellency assay system, time of observation-based testing should be considered in order to prevent an under- or overestimation of behavioral responses.Information on factors influencing the behavioral responses of mosquitoes to repellents is lacking and poorly understood, especially in the Anopheles species, night-biting mosquitoes. Our goal was to investigate the impact of different time periods on circadian activity and behavioral responses of two malaria vectors, Anopheles minimus and An. dirus, to 5% DEET using an excito-repellency test system. Each mosquito species was exposed to the repellent during the daytime (06.00–18.00) and nighttime (18.00–06.00), and time of observation was further divided into four 3-h intervals. Significant escape responses were observed between daytime and nighttime for An. minimus in both noncontact and contact tests. An. dirus showed statistical differences in contact irritancy escape response, whereas no significant difference was found in noncontact repellency tests. Both mosquito species showed more significantly higher escape responses when exposed to DEET during the afternoon and late in the night. This finding indicates that the time of testing may affect the behavioral responses of mosquitoes to repellents, especially in An. minimus and An. dirus. A better understanding of nocturnally active mosquito behavioral responses spanning from dusk to dawn would assist in optimizing product development, screening, and effective evaluation.

Low paleolatitude of the Carajás Basin at ∼2.75 Ga: Paleomagnetic evidence from basaltic flows in Amazonia

Establishing the positions of continents during the initial stages of Earth's evolution is one of the most important challenges in geosciences today. This challenge is mainly due to the severe limitations in obtaining geological and/or geophysical data from early Earth time, particularly robust paleomagnetic data. Here, we report the first paleomagnetic data from an Archean block in the Amazonian craton, the Carajás Province, for ∼2.76–2.74 billion years ago (Ga), when extensive dominantly mafic volcanism (Parauapebas Formation) covered an area of ∼18,000 km2. The paleomagnetic investigation was conducted on fresh drill cores drilled into the Carajás iron ore mine and cutting across the Parauapebas Formation. After rotating the drill core segments to geographic coordinates using the viscous magnetic component, two characteristic components, Carajás 1 and 2 (C1 and C2) were identified and further used to calculate paleomagnetic poles: C1 (∼2759 Ma; 40.5°E, −44.6°S, N = 5 A95 = 6.5°, K = 18.5) and C2 (∼2749 Ma; 342.4°E, −54.3°S, N = 28, A95 = 14.8°, K = 27.8). Pole C2 is based on a bigger number of sites, passes a reversal test and is considered robust. A baked contact test was attempted for this component, but it is not conclusive. Our results, integrated with geological evidence reveals that the Carajás block occupied low latitudes at the time, and could have been part of the Superia supercraton during the Neoarchean (∼2.75 Ga) at equatorial latitudes. Finally, a consistent succession of six magnetic reversal events was identified in the lava flow sequence from the Parauapebas Formation, pointing to an already dynamic geodynamo pre-2.7 Ga.

Gelatin Reinforced with CNCs as Nanocomposite Matrix for Trichoderma harzianum KUEN 1585 Spores in Seed Coatings.

Increasing interest on sustainable agriculture has led to the development of new materials which can be used as seed coating agents. In this study, a new material was developed based on gelatin film reinforced with cellulose nanocrystals (CNC) which was further used as nanocomposite matrix for Trichoderma harzianum KUEN 1585 spores. The nanocomposite films were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM), showing the formation of new hydrogen bonds between the components with a good compatibility between them. Measurements of water contact angles and tests of water vapor sorption and swelling degree revealed an improvement in the water vapor absorption properties of the films as a result of their reinforcement with CNC. Furthermore, by adding the Trichoderma harzianum KUEN 1585 spp. in the seed coating material, the germination percentage, speed of germination and roots length of the corn seeds improved. The polymeric coating did not inhibit the growth of T. harzianum KUEN 1585, with this material being a good candidate in modern agriculture.

An approximate model to describe the size effects of spherical contact tests, based on a modified couple stress elasticity

An approximate model to describe the size effects of spherical contact tests, based on a modified couple stress elasticity

Daily testing for contacts of individuals with SARS-CoV-2 infection and attendance and SARS-CoV-2 transmission in English secondary schools and colleges: an open-label, cluster-randomised trial

BackgroundSchool-based COVID-19 contacts in England have been asked to self-isolate at home, missing key educational opportunities. We trialled daily testing of contacts as an alternative to assess whether this resulted in similar control of transmission, while allowing more school attendance.MethodsWe did an open-label, cluster-randomised, controlled trial in secondary schools and further education colleges in England. Schools were randomly assigned (1:1) to self-isolation of school-based COVID-19 contacts for 10 days (control) or to voluntary daily lateral flow device (LFD) testing for 7 days with LFD-negative contacts remaining at school (intervention). Randomisation was stratified according to school type and size, presence of a sixth form, presence of residential students, and proportion of students eligible for free school meals. Group assignment was not masked during procedures or analysis. Coprimary outcomes in all students and staff were COVID-19-related school absence and symptomatic PCR-confirmed COVID-19, adjusted for community case rates, to estimate within-school transmission (non-inferiority margin <50% relative increase). Analyses were done on an intention-to-treat basis using quasi-Poisson regression, also estimating complier average causal effects (CACE). This trial is registered with the ISRCTN registry, ISRCTN18100261.FindingsBetween March 18 and May 4, 2021, 204 schools were taken through the consent process, during which three decided not to participate further. 201 schools were randomly assigned (control group n=99, intervention group n=102) in the 10-week study (April 19–May 10, 2021), which continued until the pre-appointed stop date (June 27, 2021). 76 control group schools and 86 intervention group schools actively participated; additional national data allowed most non-participating schools to be included in analysis of coprimary outcomes. 2432 (42·4%) of 5763 intervention group contacts participated in daily contact testing. There were 657 symptomatic PCR-confirmed infections during 7 782 537 days-at-risk (59·1 per 100 000 per week) in the control group and 740 during 8 379 749 days-at-risk (61·8 per 100 000 per week) in the intervention group (intention-to-treat adjusted incidence rate ratio [aIRR] 0·96 [95% CI 0·75–1·22]; p=0·72; CACE aIRR 0·86 [0·55–1·34]). Among students and staff, there were 59 422 (1·62%) COVID-19-related absences during 3 659 017 person-school-days in the control group and 51 541 (1·34%) during 3 845 208 person-school-days in the intervention group (intention-to-treat aIRR 0·80 [95% CI 0·54–1·19]; p=0·27; CACE aIRR 0·61 [0·30–1·23]).InterpretationDaily contact testing of school-based contacts was non-inferior to self-isolation for control of COVID-19 transmission, with similar rates of symptomatic infections among students and staff with both approaches. Infection rates in school-based contacts were low, with very few school contacts testing positive. Daily contact testing should be considered for implementation as a safe alternative to home isolation following school-based exposures.FundingUK Government Department of Health and Social Care.

Evaluation of Heartwood Extracts Combined with Linseed Oil as Wood Preservatives in Field Tests in Southern Mississippi, USA

Simple SummaryWood is a sustainable building material with a wide range of applications. Being of biological origin, wood is subject to degradation by several organisms, including termites and decay fungi. Chemical preservatives are often used to protect the wood from biodegradation but concerns regarding the overall safety and availability of chemical preservatives has stimulated research into alternative treatment methods. One approach is transferring heartwood extracts of durable wood species to non-durable wood due to their intrinsic antimicrobial properties, renewability, and perceived lower impact on the environment. Although they are not free of limitations, their efficacy can potentially be improved with methods such as co-impregnating wood with other plant-based hydrophobic chemicals. In the current study, we used heartwood extracts of four wood species and linseed oil to impregnate two non-durable wood species. Results show that co-impregnation with individual heartwood species extract, and oil increased the resistance of non-durable wood against termites and decay fungi. However, their effectiveness to protect was less than chemical preservatives. Further research is needed to examine single-extract component isolates combined with oils as well as possible synergists or co-biocides to enhance overall performance.Heartwood extracts of naturally durable wood species are often evaluated as alternatives to chemical wood preservatives, but field data from long-term performance testing are lacking. The current study evaluated the long-term (five-year) performance of two non-durable wood species treated with heartwood extracts of either Tectona grandis, Dalbergia sissoo, Cedrus deodara, or Pinus roxburghii alone or combined with linseed oil. Stakes (45.7 × 1.9 × 1.9 cm) and blocks (12.5 × 3.75 × 2.5 cm) cut from the sapwood of cottonwood and southern pine were vacuum-pressure impregnated with the individual heartwood species extract, linseed oil, or a mixture of each individual wood extract and linseed oil. For comparison, solid heartwood stakes and blocks of the wood species used to obtain extracts were also included in the tests. All samples were exposed for five years to decay and termites at a test site in southern Mississippi using ground contact (AWPA E7) and ground proximity (AWPA E26) tests. Results showed that extract-oil mixtures imparted higher termite and decay resistance in cottonwood and southern pine than linseed oil only or the individual heartwood species extract in both tests. However, these treatments were as not effective as to commercially used wood preservatives, copper naphthenate (CuN) or disodium octaborate tetrahydrate (DOT) in either test. Moreover, solid heartwood P. roxburghii stakes were completely decayed and attacked by termites after five years in the ground contact test. In contrast, C. deodara stakes were slightly attacked by termites and moderately attacked by decay fungi. However, T. grandis and D. sissoo stakes showed slight to superficial attack by termites and decay fungi in ground contact test. In contrast, T. grandis and D. sissoo blocks showed slight decay fungi attack in above-ground tests. However, termites did not attack T. grandis, D. sissoo, and C. deodara blocks. However, decay fungi moderately attacked C. deodara blocks, and P. roxburghii blocks were severely attacked by decay fungi and termites in the above-ground test.

Study on a novel backlash-adjustable worm drive via the involute helical beveloid gear meshing with dual-lead involute cylindrical worm

This paper focuses on a novel backlash-adjustable worm drive, and it is composed of a dual-lead involute cylindrical (DIC) worm and an involute helical beveloid (IHB) gear. It is characterized by the low error sensitivity, easy to manufacture and with the backlash-adjustable. The design criteria for the novel worm drive are presented based on a variable-lead and variable-thickness media rack. Then the mathematical model and meshing performance analysis model are deduced and established, and the theory of backlash-adjustable is proposed. The tooth contact analysis (TCA) is conducted by the numerical calculation and stress analysis. Moreover, the experimental gearbox is manufactured, and the contact tests and transmission accuracy tests are completed. These results indicate that the novel worm drive can effectively adjust backlash without affecting the transmission accuracy. This theoretical research provides the theoretical support for further analysis and application of the novel backlash-adjustable worm drive.

The Impact of Covid-19 and Social Protection Programs on Poverty in Indonesia

Covid-19 remained the largest challenge for the Indonesian economy in 2021. In particular, Covid-19 case numbers hit a new high of about 50,000 cases per day in mid-July. In response, the government increased the contact tracing and testing of suspected positive cases, expanded its Covid-19 vaccination drive and introduced stricter mobility and activity restrictions (PPKM Darurat/PPKM Levels 1–4). By the end of October, more than 57% of the target population had received at least one dose of a Covid-19 vaccine. The economy also improved in the first half of 2021. Building on the trough in GDP in the second quarter of 2020, economic growth returned in the second and third quarters of 2021 after contractions in the previous four quarters. Macroeconomic circumstances were also generally favourable, though significant longer-term risks remain. In terms of real wages, however, the recovery tended to benefit the formal sector and well-educated workers, while real wages in the informal sector and for low-educated workers continued to decline. At the same time, the rise in Covid-19 cases and the implementation of stricter mobility and activity restrictions have lowered expectations for economic growth in the second half of 2021. To mitigate the social and economic impact of the pandemic, the government has re-expanded its social protection programs. We find that these programs have mitigated the impact of Covid-19 on the poverty rate by four percentage points, or by about three-quarters—poverty increased to nearly 10%, rather than the 14% that would have been likely without the increased social assistance. The possibility of a K-shaped recovery implies that special social protection programs must continue as the economy recovers from the pandemic, to ensure that the poor and vulnerable are not left behind.

In vitro Investigation of the Antimicrobial Activity of Mouth Washes Incorporating Zein-Coated Magnesium Oxide Nanoparticles.

PurposeThis in vitro study was undertaken to investigate the antimicrobial effect of distinctive oral mouth washes after the addition of zein-coated (Magnesium oxide) MgO nanoparticles on exemplary of some oral microorganisms.Materials and MethodsThree hundred and twelve samples were used in this study. A set of five concentrations of MgO nanoparticles with zein and without zein-coating were incorporated into three oral mouth washes: Listerine zero, Listerine total control and Oral B in the mass percentages of 0.3%, 0.5%, 1%, 2%, 5% and 10%, in addition to controls with no MgO nanoparticles. The antimicrobial effect of three mouth washes with variable concentrations of MgO was tested against the following organisms: Staphylococcus aureus, Streptococcus mutans, Enterococcus faecalis and Candida albicans using the disc diffusion test (DDT) and direct contact test (DCT). Data were analyzed using one-way ANOVA statistical test.ResultsThe tested mouthwashes with zein-coated MgO nanoparticles showed significant differences of antimicrobial activity on S. mutans, S. aureus, E. faecalis, and C. albicans in the disc diffusion test. While in the DCT, all tested mouthwashes with MgO nanoparticles with and without zein coating showed antimicrobial activity on all tested microorganisms.ConclusionZein-coated MgO nanoparticles may be considered as a potential antimicrobial agent when added to oral mouthwashes. Future analysis, including in vivo studies, is required in order to incorporate zein/MgO nanoparticles into oral mouthwashes that may improve its antibacterial property.

Study on the regulation of polythiophene whiskers by electric field induction and the anisotropy of the film surface

AbstractIn recent years, polythiophene (P3HT) has become a kind of typical conjugated polymer material which is suitable to use on a large scale. However, it is difficult to obtain long P3HT fibers with a highly ordered arrangement due to the entanglement of molecular chains and inherent flexibility. In this work, P3HT fibers were successfully constructed and assembled by an electric‐field‐induced technique, which can be observed directly. The orientation of the P3HT molecules was confirmed by Raman and UV absorption spectra. The excellent anisotropic sliding properties of the surface of the assembled fibers were characterized by the water contact test. This work provides an idea for the preparation of smart sensing materials and lays a foundation for the wider application of P3HT. © 2021 Society of Chemical Industry

Exploring the reasons for low pertussis vaccine effectiveness in Ontario, Canada, 2006-2008: a Canadian Immunization Research Network study.

Although pertussis vaccines have been widely used for many decades, a burden of illness persists. Resurgences in Ontario, Canada, have not been substantial in the past decade, but an outbreak of pertussis occurred in Toronto between 1 October 2005 and 31 March 2006. Previous Ontario studies found high vaccine effectiveness (VE) in the initial years post-immunization. In order to explore the impact of outbreaks and external factors on VE, we investigated pertussis VE during the period 2006-2008. We assessed pertussis VE using a frequency-matched case-control study for the period 1 March 2006 to 31 December 2008. We used logistic regression to estimate VE by age, time since last vaccination, and vaccination status according to the Ontario recommended schedule. We compared analyses including and excluding cases from Toronto, and to two recent Ontario pertussis VE studies. We included 1797 confirmed cases and 7188 matched controls. Most cases were under 4 years of age during the study period. Pertussis VE was 3.8% (95% CI: - 21.0, 24.0) in the period 15-364 days following the last pertussis vaccine dose, and increased with increasing time since vaccination. Pertussis VE in the first 15-364 days excluding Toronto increased to 57.1% (95% CI: 26.0, 75.1), but the trend of increasing VE with time since vaccination persisted. Although VE was higher in older (6-11 years) than younger (0-5 years) children, it was lower at 12-13 years than after 14 years. VE was lower in comparison with other studies conducted in Ontario, particularly in younger children. Various factors occurring during the study period may have influenced the results, including clinical testing of asymptomatic contacts, laboratory testing and methods and reporting practice, and a sensitive case definition. Further studies are needed to optimize methods for measuring VE to inform pertussis vaccine policy.