Search Results (12)

Metabolic engineering presents the possibility of creating novel and practical whole-cell biocatalysts. The practice of metabolic engineering is achieved first by in vitro DNA assembly, followed by the introduction of the newly constructed DNA into industrial microorganisms to create a novel phenotype. Although this approach of in vitro DNA assembly has been studied extensively, generation of unwanted recombinant DNA products remains a possibility. In this study, a recombinant DNA, namely pGRN02, was constructed using the sequence- and ligation- independent cloning. However, this DNA assembly method had a low success rate (5%). Unexpectedly, we identified an un-wanted recombinant DNA product as a major recombinant product (70%). DNA sequencing of this product indicated that it should not have been formed during in vitro DNA assembly, but rather post in vitro assembly. This study aims to report and discuss profound results of the DNA assembly reaction. The standard SLIC design using 20 bp homology arms is theoretically sufficient for correct assembly under typical conditions. However, longer unexpected repeats, such as the 44 bp internal homology observed here, can outcompete the designed junctions and dominate the recombination outcome. Full article

Background: Although the safety of COVID-19 vaccines has been demonstrated in clinical trials, real-world pharmacovigilance remains essential to detect rare or unexpected adverse events following immunization (AEFI). In Mexico, the national AEFI surveillance system is in place, yet there is limited analysis of state-level data. Objective: To characterize AEFI related to five COVID-19 vaccines and identify factors associated with AEFI type and seriousness in Nuevo León, Mexico. Methods: A retrospective analysis of the State of Nuevo León AEFI database was conducted, including all AEFI reports between December 2020 and June 2022 (n = 2213). Data included patient sex, age, vaccine type (Pfizer/BioNTech, AstraZeneca, Sinovac, Moderna, CanSino), number of doses (1 or ≥2), symptom categories, and AEFI seriousness. Symptoms were classified as local or systemic and grouped by organ systems. Descriptive analysis and binary multivariate logistic regression were used to examine associations between demographic and vaccine-related factors with AEFI type and severity. Odds ratios (OR) with 95% confidence intervals (CI) were estimated. Results: Most AEFI reports involved females aged 19–59 years and occurred after the first vaccine dose. The most frequently reported unexpected adverse events (UAEs) were mild to moderate, including injection-site reactions, headache, chills, fatigue, nausea, fever, dizziness, weakness, myalgia, and tachycardia. The Pfizer/BioNTech vaccine was associated with higher odds of arm pain and lower odds of hemorrhagic events. Receiving ≥2 doses increased the odds of arm pain and systemic symptoms. Less than 3% of AEFIs were classified as serious. Older adults (≥65 years) and second vaccine doses were associated with increased odds of a serious AEFI, while female sex and receiving the Pfizer/BioNTech vaccine were associated with reduced odds. Conclusions: In Nuevo León, most AEFIs related to COVID-19 vaccination were mild to moderate and resolved without complications. Serious AEFIs were uncommon, with older age and second doses associated with higher risk, and female sex and Pfizer/BioNTech vaccination associated with lower risk. These findings provide a local perspective on vaccine safety that complements national and international evidence. Full article

In this study, RM (red mud) was acidified with sulfuric acid, and the acidified ARM (acidified red mud) was utilized as an innovative adsorption material for treating antibiotic-containing wastewater. The adsorption conditions, kinetics, isotherms, thermodynamics, and mechanism of ARM for CIP (ciprofloxacin) were investigated. The characterization of the ARM involved techniques such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET), X-ray diffraction (XRD), X-ray fluorescence (XRF), thermogravimetric analysis (TGA), and NH₃-TPD analysis. Adsorption studies employed a response surface methodology (RSM) for the experimental design. The results showed that ARM can absorb CIP effectively. The RSM optimal experiment indicated that the most significant model terms influencing adsorption capacity were solution pH, CIP initial concentration, and ARM dosage, under which the predicted maximum adsorption capacity achieved 7.30 mg/g. The adsorption kinetics adhered to a pseudo-second-order model, while equilibrium data fitted the Langmuir–Freundlich isotherm, yielding maximum capacity values of 7.35 mg/g. The adsorption process occurred spontaneously and absorbed heat, evidenced by ΔG^θ values between −83.05 and −91.50 kJ/mol, ΔS^θ at 281.6 J/mol/K, and ΔH^θ at 0.86 kJ/mol. Analysis using attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR) indicated a complex reaction between the Al–O in the ARM and the ester group –COO in CIP. The C=O bond in CIP was likely to undergo a slight electrostatic interaction or be bound to the internal spherical surface of the ARM. The findings indicate that ARM is a promising and efficient adsorbent for CIP removal from wastewater. Full article

Since robotic arms operating close to people are becoming increasingly common, there is a need to better understand how they can be made safe when unintended contact occurs, while still providing the required performance. Several actuators and methods for improving robot safety are studied and compared in this paper. A robotic arm moving its end effector horizontally and colliding with a person’s head is simulated. The use of a conventional electric actuator (CEA), series elastic actuator (SEA), pneumatic actuator (PA) and hybrid pneumatic electric actuator (HPEA) with model-based controllers are studied. The addition of a compliant covering to the arm and the use of collision detection and reaction strategies are also studied. The simulations include sensor noise and modeling error to improve their realism. A systematic method for tuning the controllers fairly is proposed. The motion control performance and safety of the robot are quantified using root mean square error (RMSE) between the desired and actual joint angle trajectories and maximum impact force (MIF), respectively. The results show that the RMSE values are similar when the CEA, SEA, and HPEA drive the robot’s first joint. Regarding safety, using the PA or HPEA with a compliant covering can reduce the MIF below the safety limit established by the International Organization for Standardization (ISO). To satisfy this ISO safety limit with the CEA and SEA, a collision detection and reaction strategy must be used in addition to the compliant covering. The influences of the compliant covering’s stiffness and the detection delay are also studied. Full article

Mpox Virus (MPXV) is a zoonotic infectious disease first identified in 1970 in rural villages in rainforest areas of central and western Africa when smallpox was in the final stages of eradication. Since May 2022, cases and sustained transmission chains of monkeypox have been reported for the first time in countries where the disease is not endemic and without cases having direct or immediate epidemiological links to areas of West or Central Africa (travel, importation of mammals). On 23 July 2022, WHO declared monkeypox a “Public Emergency of International Concern” (PHEIC). In this paper, we report two cases of a Polymerase Chain Reaction (PCR)-confirmed MPXV infection. A 39-year-old Italian male came to our attention for a suspected herpetic infection, fever, headache, and malaise, which were followed by the development of an erythematous plaque covered by vesicles on the chin, an oval ulcer with a white peripheral border on the lower lip, and a central erosive area and three pustules on the arms and trunk. During the physical examination, cervical lymphadenopathy was also detected. PCR investigation of the patient and his partner confirmed the presence of MPXV infection. Our report describes a possible clinical feature of Mpox disease and illustrates the challenge of a disease that seems to present itself in different ways. Full article

Development of U-type pre-stressed girders has been attempted to increase the length of I-type girders in South Korea. However, a length of 30 m or less is common because the self-weight, according to the post-tension method, is large. In this study, the pre-tension method was applied without limiting the post-tension method to induce a reduction in self-weight and in the materials used because of the decrease in the cross section. In addition, the authors proposed an application of an on-site pre-tensioning method using the internal reaction arm of a U-type girder. A pre-stressed concrete U-type girder bridge is composed of a concrete deck slab and a composite section. Structural performance characteristics, such as resistance and rigidity, were improved compared to those of the PSC I-type girders. Construction safety is also improved in the manufacturing and installation stages, and the elongation ratio is reduced because of the reduction in the weight of the girders. Therefore, it is possible to ensure the aesthetic landscape and economic efficiency of bridges. As a result, it is expected that efficient construction will be possible with high-quality factory-made and cast-in-place members. In this study, the pre-tension method is introduced in the field, and the analytical performance of the anchoring block used for tension is verified. Full article

The copper powder produced by electrolysis has a dendritic structure, which gives it excellent green strength as a raw material for producing powder metallurgical components. Yet its large specific surface makes it susceptible to oxidation. Although the oxidation tends to occur only on the surface, it still needs to be reduced. The partially oxidized cauliflower-like copper powder was reduced by hydrogen in this paper. Internal diffusion was found as the rate controlling step for the hydrogen reduction reaction, in which the apparent activation energy was determined to be 14.18 kJ/mol using the Arrhenius-based expression for the diffusion coefficient. Controlling copper powder particles were still compact after reduction, and the tips of dendrite arms became round and smooth. The apparent density decreased after reduction, but excess temperature led to sintering, and as a result, increased apparent density of metallic powder. Therefore, lower reduction temperature and appropriately long reduction times yielded better apparent density. These research results can provide reference for metallic powder plants. Full article

This study describes key topics of discussions on Twitter at the intersection of vaping and COVID-19 and documents public reactions to announcements from authoritative health agencies. Twitter posts containing vaping and COVID-19-related terms were collected from 1 December 2019 to 3 May 2020 (n = 23,103 posts). Text classifiers and unsupervised machine learning were used to identify topics in posts. Predominant topics included COVID-19 Respiratory Health (18.87%), COVID-19 Susceptibility (17.53%), Death (10.07%), Other COVID-19 Health Effects (9.62%), and Severity of COVID-19 (7.72%), among others. Public conversations on topics, such as Severity of COVID-19, Transmission, Susceptibility, Health Effects, Death, and Smoking cessation, were shaped by announcements from U.S. and international health agencies. Armed with the insights from this study, medical providers should be prepared to discuss vaping-related health risks with their patients in the era of COVID-19. Misconceptions around vaping as a protective behavior from, and an effective treatment against, COVID-19 should also be corrected. Full article

This review article aims to cover the most recent advances regarding the synthesis of linear ABC-type triblock terpolymers and star-shaped polymers by RAFT polymerization, as well as their self-assembly properties in aqueous solutions. RAFT polymerization has received extensive attention, as it is a versatile technique, compatible with a great variety of functional monomers and reaction conditions, while providing exceptional and precise control over the final structure, with well-defined side-groups and post-polymerization engineering potential. Linear triblock terpolymers synthesis can lead to very interesting novel ideas, since there are countless combinations of stimuli/non-stimuli and hydrophilic/hydrophobic monomers that someone can use. One of their most interesting features is their ubiquitous ability to self-assemble in different nanostructures depending on their degree of polymerization (DP), block composition, solubilization protocol, internal and external stimuli. On the other hand, star-shaped polymers exhibit a more stable nanostructure, with a distinct crosslinked core and arm blocks that can also incorporate stimuli-responsive blocks for “smart” applications. Full article

The desert locust, Schistocerca gregaria (Forskål) (Orthoptera: Acrididae), a major Old World pest, is associated with agricultural losses and undesirable societal effects. There are three broad approaches to its control: reaction, proaction, and outbreak prevention. Reaction protects crops from swarms but it is costly and disruptive. Proaction involves early intervention during outbreaks to avert further development to plague status; it is in current use because it is effective, relatively inexpensive, and it is the best available option for now. Outbreak prevention, largely unavailable since the 1970s, at least on a regional scale, will require highly sensitive surveillance to detect the onset of gregarization. Sufficiently early intervention can, hypothetically, extend desert locust recession indefinitely. While research on desert locust biology and behavior is, almost, no longer an urgent requirement to improve the efficacy of control, new priorities have arisen for developing outbreak prevention capability (and for enhancing proaction). Salient needs presently include long residual tactics for prophylactic (preventive) control in breeding areas, intervention thresholds, and improved, sustainable coordination among stakeholders at national, regional, and international levels. The most recent desert locust episode of 2020 provides an illustrative example of how prevention might have averted the entire upsurge, and how proaction in some countries contained the spread of swarms. The initial outbreak in Saudi Arabia escaped control due to unpreparedness, and impacts of armed conflict in Somalia and Yemen, which weakened surveillance and control, further contributed to the invasion of ≥22 countries, and the spraying of ≈4.9 million ha, by the end of 2020. Full article

The purpose of this study was to verify the efficacy of a single intra-articular (i.a.) injection of a hyaluronic acid-chitlac (HY-CTL) enriched with two low dosages of triamcinolone acetonide (TA, 2.0 mg/mL and 4.5 mg/mL), in comparison with HY-CTL alone, with a clinical control (TA 40 mg/mL) and with saline solution (NaCl) in an in vivo osteoarthritis (OA) model. Seven days after chemical induction of OA, 80 Sprague Dawley male rats were grouped into five arms (n = 16) and received a single i.a. injection of: 40 mg/mL TA, HY-CTL alone, HY-CTL with 2.0 mg/mL TA (RV2), HY-CTL with 4.5 mg/mL TA (RV4.5) and 0.9% NaCl. Pain sensitivity and Catwalk were performed at baseline and at 7, 14 and 21 days after the i.a. treatments. The histopathology of the joint, meniscus and synovial reaction, type II collagen expression and aggrecan expression were assessed 21 days after treatments. RV4.5 improved the local pain sensitivity in comparison with TA and NaCl. RV4.5 and TA exerted similar beneficial effects in all gait parameters. Histopathological analyses, measured by Osteoarthritis Research Society International (OARSI) and Kumar scores and by immunohistochemistry, evidenced that RV4.5 and TA reduced OA features in the same manner and showed a stronger type II collagen and aggrecan expression; both treatments reduced synovitis, as measured by Krenn score and, at the meniscus level, RV4.5 improved degenerative signs as evaluated by Pauli score. TA or RV4.5 treatments limited the local articular cartilage deterioration in knee OA with an improvement of the physical structure of articular cartilage, gait parameters, the sensitivity to local pain and a reduction of the synovial inflammation. Full article

Background: Randomized controlled trials (RCTs) are regarded as the most internally valid means of estimating the effectiveness of complex public health interventions, but the recruitment of participants can be difficult. The aim of this study was to explore factors that may have affected the recruitment of employees with musculoskeletal disorders (MSDs) to a multicenter worksite health promotion program from the perspective of recruiting case managers. Methods: Factors in recruitment to the RCT were explored using three focus group discussions with case managers. Data were processed using MAXQDA and analyzed with a combination of content and sequence analysis. Results: Findings showed that randomization is a major challenge for recruitment. Case managers adapted their communication with, and approaches to possible participants because of the randomization design and employed coping strategies to compensate for allocation into the control arm of the study. Perceptions of the superiority of the intervention group over the control group, perceptions of the (mis)match of participants to one of the groups, as well as the understanding of the necessity of randomization for effectiveness evaluations, further affected recruitment. Perceived expectations of possible participants and their (emotional) reactions to the randomization allocation also complicated recruitment. Conclusion: We were able to gain insight into the challenges of randomization for the recruitment of participants to a multicenter RCT. This study assisted the development of strategies to overcome barriers in the ongoing implementation process of the trial (i.e., the adaption of best practice information sheets and newsletters). There remains a need to develop effective interventions to help those recruiting to trials. Full article