Sensitivity and Selectivity on Aptamer-Based Assay: The Determination of Tetracycline Residue in Bovine Milk

A competitive enzyme-linked aptamer assay (ELAA) to detect tetracycline in milk was performed by using two different aptamers individually; one is 76 mer-DNA aptamer and the other is 57 mer-RNA aptamer. The best optimum condition was obtained without monovalent ion, Na+ and also by adding no Mg2+ ion in the assay buffer, along with RT incubation. The optimized ELAA showed a good sensitivity (LOD of 2.10 × 10−8 M) with a wide dynamic range (3.16 × 10−8 M ~ 3.16 × 10−4 M). In addition, the average R.S.D. across all data points of the curve was less than 2.5% with good recoveries (~101.8%) from the milk media. Thus, this method provides a good tool to monitor tetracycline in milk from MRLs' point of view. However, this ELAA method was not superior to the ELISA method in terms of specificity. This paper describes that it does not always give better sensitivity and specificity in assays even though aptamers have several advantages over antibodies and have been known to be good binders for binding assays

Semiconductor clusters: Synthetic precursors for colloidal quantum dots

Semiconductor clusters have been implicated as reaction intermediates between molecular precursors and colloidal quantum dots (CQDs). The success of isolation of semiconductor clusters have enabled detailed investigation of the atomic information of semiconductor clusters. The identification of atomic information has emerged as an important topic because knowledge of the structure-function relationship of intermediate clusters has been helpful to reveal the synthetic mechanism of CQDs. Recently, they have been utilized as the synthetic precursors for CQDs, which was not readily achieved using conventional molecular precursors. This mini review briefly introduces the current understanding of their atomic information such as the composition, structure, and surface. We then discuss advantages, limitations, and the perspective of semiconductor clusters as a precursor for synthesis of CQDs

Age of first experience of gender incongruence among transgender and non-binary individuals

Objective Gender incongruence (GI) is a condition in which an individual’s gender identity, role, and expression differ from their assigned sex. This study aimed to evaluate when GI first arises in transgender and non-binary individuals seeking hormone therapy and their years living untreated in South Korea. Methods This retrospective study analyzed GI patients seeking gender-affirming hormone therapy (GAHT) or surgery between 2015 and 2021. The recorded data included gender identity, legal transition status, age of onset of GI, age at the initiation of therapy, and total therapy duration. Results In total, 337 patients were enrolled, including 149 (44.2%) transgender men, 153 (45.4%) transgender women, and 35 (10.4%) non-binary individuals. The mean age of onset of GI was 10.6 years (standard deviation, 5.1). Of the total patients, 29% had an onset of GI before age 6 years (preschool), 61% before age 12 (elementary-school), and 87% before age 15 (middle-school). Patients lived with GI for almost 14 years before GAHT initiation at a median age of 23.0 years. 90% of transgender men, 82.3% of transgender women, and 85% of non-binary patients disclosed their gender identities to their families. Regarding social transition, 31.5% of transgender men, 16.3% of transgender women, and none of the non-binary patients (P<0.005) changed their legal gender markers. Conclusion Many transgender and non-binary individuals experience GI early in life. These findings emphasized the need for early evaluation, timely gender-affirming care, and more accessible legal processes for gender marker changes in South Korea, aiming to enhance the safety and well-being of these individuals

Association of sodium-glucose cotransporter 2 inhibitors with post-discharge outcomes in patients with acute heart failure with type 2 diabetes:a cohort study

BACKGROUND: Given the cumulative evidence on the effectiveness of sodium-glucose cotransporter 2 inhibitors (SGLT2is) on chronic heart failure, demand is emerging for further information on their effects in patients who are hospitalized for acute heart failure. However, there is still limited evidence about the class effect of SGLT2is on acute heart failure. We investigated whether initiating treatment with SGLT2is after an episode of acute heart failure reduces the risks of post-discharge heart failure readmission or cardiovascular mortality among patients with type 2 diabetes. METHODS: A retrospective cohort study was conducted in a cohort of patients with type 2 diabetes who hospitalized for heart failure, using Korean Health Insurance Review & Assessment database (2015-2020). The exposure was defined as initiation of SGLT2is during hospitalization or at discharge. We assessed hazards of post-discharge heart failure readmission and cardiovascular death at 1-year, and 30-, 60-, and 90-day from the date of discharge in the SGLT2is users and non-users. Cox proportional hazards models with propensity score-based inverse probability of treatment weighting were used to estimate hazard ratios and 95% confidence intervals. RESULTS: Among 56,343 patients with type 2 diabetes hospitalized for heart failure, 29,290 patients were included in the study cohort (mean [SD] age, 74.1 [10.8] years; 56.1% women); 818 patients (2.8%) were prescribed SGLT2is during index hospitalization or at discharge. Patients with a prescription for SGLT2i vs. those without prescription had lower rates of heart failure readmission or cardiovascular death at 1 year (22.4% vs. 25.3%; adjusted hazard ratio, 0.90 [95% confidence interval, 0.87-0.93]), and also at 30 days (7.0% vs. 7.7%%; 0.74 [0.69-0.79]). CONCLUSIONS: Among patients with type 2 diabetes, initiating SGLT2i treatment after an episode of acute heart failure was significantly associated with a reduced combined risk of heart failure readmission and cardiovascular mortality in a nationwide cohort reflecting routine clinical practice

A Mechanistic Analysis of Phase Evolution and Hydrogen Storage Behavior in Nanocrystalline Mg(BH4)2 within Reduced Graphene Oxide.

Magnesium borohydride (Mg(BH4)2, abbreviated here MBH) has received tremendous attention as a promising onboard hydrogen storage medium due to its excellent gravimetric and volumetric hydrogen storage capacities. While the polymorphs of MBH-alpha (α), beta (β), and gamma (γ)-have distinct properties, their synthetic homogeneity can be difficult to control, mainly due to their structural complexity and similar thermodynamic properties. Here, we describe an effective approach for obtaining pure polymorphic phases of MBH nanomaterials within a reduced graphene oxide support (abbreviated MBHg) under mild conditions (60-190 °C under mild vacuum, 2 Torr), starting from two distinct samples initially dried under Ar and vacuum. Specifically, we selectively synthesize the thermodynamically stable α phase and metastable β phase from the γ-phase within the temperature range of 150-180 °C. The relevant underlying phase evolution mechanism is elucidated by theoretical thermodynamics and kinetic nucleation modeling. The resulting MBHg composites exhibit structural stability, resistance to oxidation, and partially reversible formation of diverse [BH4]- species during de- and rehydrogenation processes, rendering them intriguing candidates for further optimization toward hydrogen storage applications

Tailored growth of single-crystalline InP tetrapods

Despite the technological importance of colloidal covalent III-V nanocrystals with unique optoelectronic properties, their synthetic process still has challenges originating from the complex energy landscape of the reaction. Here, we present InP tetrapod nanocrystals as a crystalline late intermediate in the synthetic pathway that warrants controlled growth. We isolate tetrapod intermediate species with well-defined surfaces of (110) and ((1) over bar(1) over bar(1) over bar) via the suppression of further growth. An additional precursor supply at low temperature induces [(1) over bar(1) over bar(1) over bar]-specific growth, whereas the [110]-directional growth occurs over the activation barrier of 65.7 kJ/mol at a higher temperature, thus finalizes into the (111)-faceted tetrahedron nanocrystals. We address the use of late intermediates with well-defined facets at the sub-10 nm scale for the tailored growth of covalent III-V nanocrystals and highlight the potential for the directed approach of nanocrystal synthesis

Cardiovascular safety of evogliptin dual and triple therapy in patients with type 2 diabetes: a nationwide cohort study

Objective: To investigate the risk of cardiovascular events associated with commonly used dual and triple therapies of evogliptin, a recently introduced dipeptidyl peptidase-4 inhibitor (DPP4i), for managing type 2 diabetes in routine clinical practice. Design: A retrospective cohort study. Setting: Korean Health Insurance Review and Assessment database. Participants: Patients who initiated metformin-based dual therapy and metformin+sulfonylurea-based triple therapy in South Korea from 2014 to 2018. Interventions: Initiation of combination therapy with evogliptin. Primary and secondary outcome measures: Hazards of cardiovascular events, a composite endpoint of myocardial infarction, heart failure and cerebrovascular events, and its individual components. Cox proportional hazards model with propensity score-based inverse probability of treatment weighting were used to estimate HRs and 95% CIs. Results: From the dual and triple therapy cohorts, 5830 metformin+evogliptin users and 2198 metformin+sulfonylurea+evogliptin users were identified, respectively. Metformin+evogliptin users, as compared with metformin+non-DPP4i, had a 29% reduced risk of cardiovascular events (HR 0.71, 95% CI 0.62 to 0.82); HRs for individual outcomes were cerebrovascular events (0.71, 95% CI 0.53 to 0.95), heart failure (0.70, 95% CI 0.59 to 0.82), myocardial infarction (0.89, 95% CI 0.60 to 1.31). Metformin+sulfonylurea+evogliptin users, compared with metformin+sulfonylurea+non-DPP4i, had a 24% reduced risk of cardiovascular events (0.76, 95% CI 0.59 to 0.97); HRs for individual outcomes were myocardial infarction (0.57, 95% CI 0.27 to 1.19), heart failure (0.74, 95% CI 0.55 to 1.01), cerebrovascular events (0.96, 95% CI 0.61 to 1.51). Conclusions: These findings suggest that dual or triple therapies of evogliptin for the management of type 2 diabetes in routine clinical practice present no cardiovascular harms, but could alternatively offer cardiovascular benefits in this patient population

CRISPR/Cas9-induced knockout and knock-in mutations in Chlamydomonas reinhardtii

Genome editing is crucial for genetic engineering of organisms for improved traits, particularly in microalgae due to the urgent necessity for the next generation biofuel production. The most advanced CRISPR/Cas9 system is simple, efficient and accurate in some organisms; however, it has proven extremely difficult in microalgae including the model alga Chlamydomonas. We solved this problem by delivering Cas9 ribonucleoproteins (RNPs) comprising the Cas9 protein and sgRNAs to avoid cytotoxicity and off-targeting associated with vector-driven expression of Cas9. We obtained CRISPR/Cas9-induced mutations at three loci including MAA7, CpSRP43 and ChlM, and targeted mutagenic efficiency was improved up to 100 fold compared to the first report of transgenic Cas9-induced mutagenesis. Interestingly, we found that unrelated vectors used for the selection purpose were predominantly integrated at the Cas9 cut site, indicative of NHEJ-mediated knock-in events. As expected with Cas9 RNPs, no off-targeting was found in one of the mutagenic screens. In conclusion, we improved the knockout efficiency by using Cas9 RNPs, which opens great opportunities not only for biological research but also industrial applications in Chlamydomonas and other microalgae. Findings of the NHEJ-mediated knock-in events will allow applications of the CRISPR/Cas9 system in microalgae, including safe harboring techniques shown in other organisms.

CRISPR/Cas9-induced knockout and knock-in mutations in Chlamydomonas reinhardtii

Genome editing is crucial for genetic engineering of organisms for improved traits, particularly in microalgae due to the urgent necessity for the next generation biofuel production. The most advanced CRISPR/Cas9 system is simple, efficient and accurate in some organisms; however, it has proven extremely difficult in microalgae including the model alga Chlamydomonas. We solved this problem by delivering Cas9 ribonucleoproteins (RNPs) comprising the Cas9 protein and sgRNAs to avoid cytotoxicity and off-targeting associated with vector-driven expression of Cas9. We obtained CRISPR/Cas9-induced mutations at three loci including MAA7, CpSRP43 and ChlM, and targeted mutagenic efficiency was improved up to 100 fold compared to the first report of transgenic Cas9-induced mutagenesis. Interestingly, we found that unrelated vectors used for the selection purpose were predominantly integrated at the Cas9 cut site, indicative of NHEJ-mediated knock-in events. As expected with Cas9 RNPs, no off-targeting was found in one of the mutagenic screens. In conclusion, we improved the knockout efficiency by using Cas9 RNPs, which opens great opportunities not only for biological research but also industrial applications in Chlamydomonas and other microalgae. Findings of the NHEJ-mediated knock-in events will allow applications of the CRISPR/Cas9 system in microalgae, including "safe harboring" techniques shown in other organisms142561sciescopu