Background Highly sensitive real-time reverse transcription polymerase chain reaction (RT-qPCR) methods have been developed for the detection of SARS-CoV-2. However, they are costly. Loop-mediated isothermal amplification (LAMP) assay has emerged as a novel alternative isothermal amplification method for the detection of nucleic acid. Methods A rapid, sensitive and specific real-time reverse transcription LAMP (RT-LAMP) assay was developed for SARS-CoV-2 detection. Results This assay detected one copy/reaction of SARS-CoV-2 RNA in 30 min. Both the clinical sensitivity and specificity of this assay were 100%. The RT-LAMP showed comparable performance with RT-qPCR. Combining simplicity and cost-effectiveness, this assay is therefore recommended for use in resource resource-limited settings.

Rapid diagnosis is an important intervention in managing the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) outbreak. Real time reverse transcription polymerase chain reaction (RT-qPCR) remains the primary means for diagnosing the new virus strain but it is time consuming and costly. Recombinase polymerase amplification (RPA) is an isothermal amplification assay that does not require a PCR machine. It is an affordable, rapid, and simple assay. In this study, we developed and optimized a sensitive reverse transcription (RT)-RPA assay for the rapid detection of SARS-CoV-2 using SYBR Green I and/or lateral flow (LF) strip. The analytical sensitivity and specificity of the RT-RPA assay were tested by using 10-fold serial diluted synthetic RNA and genomic RNA of similar viruses, respectively. Clinical sensitivity and specificity of the RT-RPA assay were carried out using 78 positive and 35 negative nasopharyngeal samples. The detection limit of both RPA and RT-qPCR assays was 7.659 and 5 copies/μL RNA, respectively with no cross reactivity with other viruses. The clinical sensitivity and specificity of RT-RPA were 98% and 100%, respectively. Our study showed that RT-RPA represents a viable alternative to RT-qPCR for the detection of SARS-CoV-2, especially in areas with limited infrastructure.

Kratom (Mitragynaspeciosa), a natural existing plant found in South-East Asia, is tradi-tionally used as an herb to help to elevate a person's energy and also to treat numerous medical ailments. Other than the analgesic property, kratom has been used as an agent to overcome opioid withdrawal as it contains natural alkaloids, i.e. mitragynine, 7-hydroxymitragynine, and MGM-9, which has agonist affinity on the opioid receptors, including mu (μ) and kappa (κ). The role of neural reward pathway linked to μ-opioid receptors and both dopaminergic and GABA-ergic interneurons that express μ-opioid receptors were deliberated. However, kratom has been reported to be abused together with other illicit substances with high risk of potential addiction. There are also anecdotes of an adverse effect and toxicity of kratom, i.e. tremor, fatigue, seizure, and death. Different countries have distinctive regulation and policy on the plantation and use of this plant when most of the countries banned the use of it because of its addiction problems and side effects. The aim of this review is to highlight on the potential use of kratom, a unique 'herbs" as a substitution therapy for chronic pain and opioid addiction, based on the neurobiological perspective of pain and the underlying mechanism of actions of drug addiction.

Rubber/metal composites are known to be highly durable in a normal atmospheric condition. However, when they are exposed to an aggressive environment such as the marine environment, they tend to fail prematurely. The failure is usually caused by the loss of adhesion of the rubber to metal substrate. The aim of this work is to elucidate the adhesion failure mechanism by using a commercial bonding system for bonded rubber/metal exposed in a marine environment. A simulation study that was carried out through a salt spray test indicated that corrosion of the exposed metal substrates induced the loss of adhesion through cathodic disbonding. Laboratory exposure in alkaline medium, cathodic disbonding, and anodic undermining tests suggested that the hydroxyl ions generated from corrosion reactions contributed to the adhesion failure.

The issues of social desirability bias and order effect bias are common problems in ethics. Methodologically, these two problems may weaken the study's validity and reliability thus, making the results of the study invalid. Utilizing vignettes in whistleblowing research may further add to these problems as the case scenario in the vignettes may enhance respondents' social desirability bias and the sequence of presentation order of vignettes may then present the problem of vignettes' order effect bias. The paper addresses these two problems by statistically examining the effects of these two types of bias within the study of whistle-blowing intentions.