Crystallographic Pathways to Tailoring Metal-Insulator Transition through Oxygen Transport in VO2.

The metal-insulator (MI) transition of vanadium dioxide (VO2) is effectively modulated by oxygen vacancies, which decrease the transition temperature and insulating resistance. Oxygen vacancies in thin films can be driven by oxygen transport using electrochemical potential. This study delves into the role of crystallographic channels in VO2 in facilitating oxygen transport and the subsequent tuning of electrical properties. A model system is designed with two types of VO2 thin films: (100)- and (001)-oriented, where channels align parallel and perpendicular to the surface, respectively. Growing an oxygen-deficient TiO2 layer on these VO2 films prompted oxygen transport from VO2 to TiO2. Notably, in (001)-VO2 film, where oxygen ions move along the open channels, the oxygen migration deepens the depleted region beyond that in (100)-VO2, leading to more pronounced changes in metal-insulator transition behaviors. The findings emphasize the importance of understanding the intrinsic crystal structure, such as channel pathways, in controlling ionic defects and customizing electrical properties for applications.

Saliva-based Proteinase K method: A rapid and reliable diagnostic tool for the detection of SARS-COV-2 in children.

Early and accurate detection of viruses in children might help prevent transmission and severe diseases. In this study, the severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) detection in children was evaluated using saliva specimens with a Proteinase K (PTK)-based RNA preparation, as saliva collection is a simple and noninvasive procedure, even in young children, with fewer concerns about sample contamination. The saliva-based PTK and the conventional paired nasopharyngeal aspiration (NPA)-based detection methods were compared between COVID-19-positive and -negative children. In addition, the detection rate for SARS-COV-2 and the difference between admission and discharge by the saliva-based PTK method was tested in COVID-19 patients. The diagnostic accuracy of the saliva-based PTK method was 98.8% compared to NP swab-based reverse transcriptase polymerase chain reaction. Saliva samples showed high sensitivity (94.1%) and specificity (100%) when using the PTK method. Furthermore, the saliva-based PTK method significantly reduced the test processing time by 2 h. Notably, Ct values at discharge increased in saliva samples compared with those at admission, which might indicate patients' clinical conditions or virus activity. In conclusion, the saliva-based PTK implemented in this study streamlines RNA extraction, making the process faster, safer, and more cost-effective, demonstrating that this method is a rapid and reliable diagnostic tool for SARS-CoV-2 detection in children.

A Study on the Retrospective Reinterpretation of BRCA1 and BRCA2 Variants.

BACKGROUND: Hereditary breast/ovarian cancer is associated with BRCA gene mutations. As large volumes of clinical data on BRCA variants are continuously updated, their clinical interpretation may change, leading to their reclassification. This study analyzed the class and proportion of the changed clinical interpretations of BRCA variants to validate the need for periodic reviews of these variants. METHODS: This retrospective study reinterpreted previously reported BRCA1 and BRCA2 exon variants according to the 2015 American College of Medical Genetics and Genomics guidelines and the clinical significance of the recent public genomic database. Reanalyzed results were obtained for patients tested for BRCA genetic mutation for 10 years and 4 months. RESULTS: We included data from 4,058 patients, with 595 having at least one pathogenic variant (P), likely pathogenic variant (LP), or variant of uncertain significance (VUS) at a detection rate of 14.66%. The numbers of exon and intron variants were 562 (87.81%) and 78 (12.19%), respectively. BRCA1 exhibited a significantly higher P/LP detection rate of 6.96% compared to that of BRCA2 at 6.89% (p < 0.001). Conversely, BRCA2 demonstrated a significantly higher VUS rate of 10.38% compared to that of BRCA1 at 5.08% (p < 0.001). Among BRCA1 mutations, substitutions were the most prevalent in P/LP and VUS. Among BRCA2 mutations, deletions were most prevalent in P/LP, and substitutions were most prevalent in VUS. Among the 131 patients with P/LP in BRCA1 exons, the clinical interpretation was reclassified in two cases (1.53%), one VUS and one benign/likely benign (B/LB), and 48 cases (48.00%) with VUS were reclassified; one to P/LP and 47 to B/LB. Among the 138 patients with P/LP in BRCA2 exons, the clinical interpretation was reclassified in six (4.35%), five to VUS, and one to B/LB, and all 74 with VUS were reclassified to B/LB. CONCLUSIONS: We determined the class and proportion of reclassified BRCA variants. In conclusion, reviews are required to provide clinical guidance, such as determining treatment direction and preventive measures in the future.

Preclinical Assessment of the PI3Kα Selective Inhibitor Inavolisib and Prediction of Its Pharmacokinetics and Efficacious Dose in Human.

1. Small molecule inhibitors of the PI3K pathway have been extensively investigated as potential anticancer agents. Among the effectors in this pathway, PI3Kα is the kinase most frequently associated with the development of tumors, through mutations and amplifications of the PIK3CA gene encoding the p110α catalytic subunit.2. Inavolisib (GDC-0077) is a potent and PI3Kα-selective inhibitor that also specifically triggers the degradation of the mutant p110α protein.3. We characterized inavolisib ADME properties in preclinical in vitro and in vivo studies, assessed its efficacy in the PIK3CA mutant KPL-4 breast cancer xenograft model, and predicted its pharmacokinetics and efficacious dose in humans.4. Inavolisib had a moderate permeability (1.9•10-6 cm/s) in MDCK cells and was a P-gp and Bcrp1 substrate. It appeared metabolically stable in hepatocytes incubations from human and preclinical species. The systemic clearance was low in mouse, monkey and dog and high in rat. Oral bioavailability ranged from 57.5% to 100%. Inavolisib was efficacious in the KPL-4 sub-cutaneous xenograft model.5. The PK/PD model parameters estimated from the efficacy study, combined with PBPK model-predicted human PK profiles, projected that a dose of 3 mg could lead to clinical response. Inavolisib is currently being tested in phase 3 trials.

Configurable Crack Wall Conduction in a Complex Oxide.

Mobile defects in solid-state materials play a significant role in memristive switching and energy-efficient neuromorphic computation. Techniques for confining and manipulating point defects may have great promise for low-dimensional memories. Here, we report the spontaneous gathering of oxygen vacancies at strain-relaxed crack walls in SrTiO3 thin films grown on DyScO3 substrates as a result of flexoelectricity. We found that electronic conductance at the crack walls was enhanced compared to the crack-free region, by a factor of 104. A switchable asymmetric diode-like feature was also observed, and the mechanism is discussed, based on the electrical migration of oxygen vacancy donors in the background of Sr-deficient acceptors forming n+-n or n-n+ junctions. By tracing the temporal relaxations of surface potential and lattice expansion of a formed region, we determine the diffusivity of mobile defects in crack walls to be 1.4 × 10-16 cm2/s, which is consistent with oxygen vacancy kinetics.

L-Fucose-Rich Sulfated Glycans from Edible Brown Seaweed: A Promising Functional Food for Obesity and Energy Expenditure Improvement.

The global obesity epidemic, exacerbated by the sedentary lifestyle fostered by the COVID-19 pandemic, presents a growing socioeconomic burden due to decreased physical activity and increased morbidity. Current obesity treatments show promise, but they often come with expensive medications, frequent injections, and potential side effects, with limited success in improving obesity through increased energy expenditure. This study explores the potential of a refined sulfated polysaccharide (SPSL), derived from the brown seaweed Scytosiphon lomentaria (SL), as a safe and effective anti-obesity treatment by promoting energy expenditure. Chemical characterization revealed that SPSL, rich in sulfate and L-fucose content, comprises nine distinct sulfated glycan structures. In vitro analysis demonstrated potent anti-lipogenic properties in adipocytes, mediated by the downregulation of key adipogenic modulators, including 5' adenosine monophosphate-activated protein kinase (AMPK) and peroxisome proliferator-activated receptor γ (PPARγ) pathways. Inhibiting AMPK attenuated the anti-adipogenic effects of SPSL, confirming its involvement in the mechanism of action. Furthermore, in vivo studies using zebrafish models showed that SPSL increased energy expenditure and reduced lipid accumulation. These findings collectively highlight the therapeutic potential of SPSL as a functional food ingredient for mitigating obesity-related metabolic dysregulation by promoting energy expenditure. Further mechanistic and preclinical investigations are warranted to fully elucidate its mode of action and evaluate its efficacy in obesity management, potentially offering a novel, natural therapeutic avenue for this global health concern.

Skin Improvement Effects of Ultrasound-Enzyme-Treated Collagen Peptide Extracts from Flatfish (Paralichthys olivaceus) Skin in an In Vitro Model.

Collagen is considered to be an intercellular adhesive that prevents tissue stretching or damage. It is widely utilized in cosmetic skin solutions, drug delivery, vitreous substitutions, 3D cell cultures, and surgery. In this study, we report the development of a green technology for manufacturing collagen peptides from flatfish skin using ultrasound and enzymatic treatment and a subsequent assessment on skin functionality. First, flatfish skin was extracted using ultrasound in distilled water (DW) for 6 h at 80 °C. Molecular weight analysis via high-performance liquid chromatography (HPLC) after treatment with industrial enzymes (alcalase, papain, protamex, and flavourzyme) showed that the smallest molecular weight (3.56 kDa) was achieved by adding papain (0.5% for 2 h). To determine functionality based on peptide molecular weight, two fractions of 1100 Da and 468 Da were obtained through separation using Sephadex™ G-10. We evaluated the effects of these peptides on protection against oxidative stress in human keratinocytes (HaCaT) cells, inhibition of MMP-1 expression in human dermal fibroblast (HDF) cells, reduction in melanin content, and the inhibition of tyrosinase enzyme activity in murine melanoma (B16F10) cells. These results demonstrate that the isolated low-molecular-weight peptides exhibit superior skin anti-oxidant, anti-wrinkle, and whitening properties.

Anti-Melanogenic Effects of a Polysaccharide Isolated from Undaria pinnatifida Sporophyll Extracts.

Undaria pinnatifida is a temperate brown alga known to exert free radical-scavenging and anti-inflammatory effects. In this study, we investigated the skin-whitening effects of U. pinnatifida sporophyll extracts (UPEs) in α-melanocyte-stimulating hormone (α-MSH)-stimulated B16F10 melanoma cells. The crude polysaccharide fraction (UPF) was obtained via ethanol precipitation. Four polysaccharide fractions (UPF1-4) were isolated and purified using ion-exchange column chromatography, and their anti-melanogenic activity was evaluated. UPF3 exhibited the highest anti-melanogenic activity, showing the highest sulfate (39.79%), fucose (143 µg/mg), and galactose (208 µg/mg) contents. UPF3 significantly inhibited intracellular tyrosinase activity in B16F10 cells. We also evaluated the melanogenic signaling pathway to determine the mechanism of action of UPF3 in melanongenesis. UPF3 reduced the expression of tyrosinase-related protein-1 (TRP-1), tyrosinase-related protein-2 (TRP-2), and tyrosinase, which play important roles in melanin production. Therefore, UPF3 has high potential for use in skin-whitening functional pharmaceuticals and cosmetics.

Evaluation of two SARS-CoV-2 IgG/IgM Rapid Tests in Capillary Blood Samples.

BACKGROUND: As COVID-19 has spread rapidly around the world, it has become essential to detect the virus quickly and accurately for disease prevention and control. Therefore, in response to the COVID-19 pandemic, the need for rapid serological point-of-care test has increased. Recently, many antibody tests have been developed to detect IgM and/or IgG to SARS-CoV-2 in human blood. The authors conducted a prospective study to evaluate the performance of a rapid chromatographic immunoassay and a fluorescent immunoassay for the qualitative detection of specific antibodies, IgM and IgG to SARS-CoV-2 in capillary blood samples, compared to the real-time RT-PCR. METHODS: The subjects included 70 patients who were confirmed positive by real-time RT-PCR and 70 people who were negative. STANDARD Q COVID-19 IgM/IgG Plus Test (chromatographic immunoassay) and Fluorescent immunoassay for IgM and IgG to SARS-CoV-2 (fluorescent immunoassay) were performed using capillary blood samples. Based on the results of real-time RT-PCR assay, clinical sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of two rapid tests were investigated. And the agreement rate between two rapid tests was also presented. RESULTS: Sensitivity, specificity, PPV and NPV of the chromatographic immunoassay were 82.9%, 98.6%, 98.3%, and 85.2%, respectively. At more than 7 days after the onset of symptoms, sensitivity increased to 87.3%. Sensitivity, specificity, PPV, and NPV were 81.4%, 100.0%, 100.0%, and 84.3%, respectively, for the fluorescent immunoassay. At more than 7 days after the onset of symptoms, sensitivity increased to 85.7%. The agreement rate of the two tests was 97.1%. CONCLUSIONS: STANDARD Q COVID-19 IgM/IgG Plus Test and STANDARD F COVID-19 IgM/IgG Combo FIA turned out very specific and sensitive enough to detect individuals infected to SARS-CoV-2. Also, these tests were simple, fast, visually interpretable, and required a small amount of capillary whole blood.

Diagnostic Performance of Interferon Gamma Release Assay (IGRA) for Cell-Mediated Immune Responses to SARS-CoV-2.

BACKGROUND: As SARS-CoV-2 infection became a pandemic, much effort has been made to measure both antibody production and T cell response to SARS-CoV-2 to diagnose COVID-19 patients or find out their immune status. Authors tried to determine the optimal cutoff value and evaluate clinical performance of one interferon-γ release assay (IGRA) kit and compared their results with serological antibody assay in COVID-19 patients. METHODS: Study subjects included 100 patients confirmed as COVID-19 with RT-PCR method and 88 healthy volunteers who were PCR negative. IGRA tests were performed using STANDARDTM E Covi-FERON ELISA. Presence of SARS-CoV-2 antibodies was detected using STANDARD Q COVID-19 IgM/IgG Plus Test. Cutoff value was assessed using receiver operating characteristic (ROC) curve. RESULTS: The cutoff value was 0.24 IU/mL and the area under the curve (AUC) of the ROC curve was 0.973 with 95% confidence interval (CI) of 0.940 - 1.005. At this cutoff value, sensitivity and specificity were 91.7% and 100%, respectively. In addition, when compared with antibody test, concordance rate was 95%. CONCLUSIONS: STANDARDTM E Covi-FERON ELISA showed high sensitivity and specificity, when the cutoff value was 0.24 IU/mL. It was also consistent with the antibody test. IGRA test was a good indicator of cellular immune response in COVID-19 patients.

The Diagnostic Yield and Difficulties of Utilizing Soft-clipped Read Clusters Encountered in Clinical Exome Sequencing.

BACKGROUND: Despite the wide use of next generation sequencing, there are still many difficulties in detecting structural variants. A split read is one of the clues of structural variants and is represented as a soft-clipped read in the raw sequencing data. Considering that most of the breakpoints of structural variants reside in non-coding regions, split read information has not been routinely used in exome sequencing or targeted panel sequencing. Recently, SCRAMble, a software capable of detecting mobile element insertion (MEI) and deletion based on soft-clipped read clusters (SCRCs), was shown to provide an additional diagnostic yield of 0.03 - 0.25%. SCRAMble is the only software that can be used for exome sequencing or targeted panel sequencing to detect structural variants based on SCRC information. The aim of present study was to establish a working procedure of utilizing SCRC information using SCRAMble in clinical exome sequencing and to assess its diagnostic yield. METHODS: Raw sequencing data of clinical exome sequencing were retrospectively analyzed using SCRAMble to search MEIs and deletions. SCRAMble software was installed according to the manufacturer's instructions and default parameters except for one, mei-score, which was adjusted for sensitivity, were used. RefSeq gene annotation was performed for both MEI and deletion calls using ANNOVAR. Blacklist-based filtering was used to reduce candidate MEI/deletion calls. Clinical relevance was manually evaluated for the remaining variant calls. RESULTS: One diagnostic MEI, which is a founder variant in East Asia, was detected in two cases (2/266, 0.75%). In addition, two diagnostic deletions, which had been previously detected in depth-of-coverage (DOC)-based copy number variant (CNV) callers, were detected (2/266, 0.75%). Base-level breakpoints that could not be derived by the DOC-based callers were identified for these two deletions using SCRAMble. Most SCRCs were repetitive among cases and blacklist-based filtering reduced candidate MEI/deletion calls by 49.5 - 94.5%, leaving a considerable number of variant calls to be manually validated. CONCLUSIONS: SCRC screening in exome or targeted panel sequencing may provide additional diagnostic yield either by pathogenic MEI detection or reassurance of deletions identified by DOC-based CNV callers. Development of an efficient filtering algorithm is warranted.

Recent Changes in the Human Metapneumovirus Outbreak at a University Hospital in Korea.

BACKGROUND: Although the detection of respiratory viruses other than severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was significantly reduced because of quarantine due to the coronavirus disease (COVID-19) pandemic, an epidemic of several viruses was reported unexpectedly. We also detected a change in the pattern of human metapneumovirus (HMPV) outbreak compared to that before the COVID-19 pandemic. Therefore, the authors intended to identify the incidence and altered distribution pattern of the HMPV outbreak and provide useful information for clinical practice. METHODS: This retrospective study investigated the incidence and distribution of HMPV from March 2020 to December 2022 during the COVID-19 pandemic. Detection of respiratory microorganisms was performed by multiplex polymerase chain reaction using a commercial kit and FilmArray assay. RESULTS: The overall incidence of at least one respiratory microorganism was 50.3% (1,152/2,290). HMPV was not detected between March 2020 and June 2022. However, it was suddenly detected in July 2022 and continued for approximately five months until November 2022. In particular, the detection rate of HMPV was high in September and October 2022, accounting for approximately 76.1% (51/67) of the total HMPV-positive cases. Seasonally, 92.5% (62/67) of HMPV cases were detected in autumn, while the rest of the cases were detected in summer. The HMPV detection rate, according to the age group, was highest in group 4 (3 - 6 years) at 7.4% (27/367), followed by group 3 (4 months to 2 years) at 3.6% (31/861). In HMPV-positive cases, the rate of more than two respiratory pathogens was 46.3% (31/67). An analysis of co-infecting pathogens showed that HMPV with rhinovirus A/B/C/ enteroviruses accounted for the highest percentage (51.6%), followed by HMPV with respiratory syncytial virus (48.4%). CONCLUSIONS: The COVID-19 pandemic has caused several changes in our lives. This study confirmed that the seasonal distribution of HMPV was different from that before the COVID-19 pandemic. Therefore, it can be assumed that the distribution of other respiratory microorganisms could have changed and it appears that changes could occur in previously known viral epidemiology. Clinicians should therefore be alert to this possibility.

Incidence and Distribution of the Pathogens Causing GI Infections at a University Hospital of Korea.

BACKGROUND: Gastrointestinal (GI) infections, caused by various pathogens such as bacteria, viruses, protozoa, and parasites, are the second most common infectious diseases. Molecular diagnostics that can simultaneously detect these pathogens are commonly used in syndromic approaches. The authors aimed to identify the causative pathogens of GI infections to provide clinically useful information. METHODS: This retrospective study used molecular diagnostic methods to determine the incidence and distribution of GI pathogens according to gender, age, and season and analyze their coinfection from August 2020 to December 2022. RESULTS: The overall incidence of at least one GI pathogen was 40.1% (991/2, 471). The positivity rates for bacteria and viruses were 33.1% (817/2, 471) and 9.2% (227/2,471), respectively; the positivity rate for bacteria was significantly higher than that for viruses (p < 0.001). The incidence of GI pathogens according to age group was highest in group 3 (59.9%), followed by group 4 (57.0%). The most common bacterial pathogen associated with GI infections was C. difficile, followed by diarrheagenic E. coli, Campylobacter spp., and Salmonella spp. Enteropathogenic E. coli accounted for a large percentage of diarrheagenic E. coli (63.6%, 157/247). Among the viral pathogens, norovirus GI/GII was the most commonly detected virus, followed by adenovirus F40/41 and rotavirus A. For bacterial- or viral-positive cases, the distribution of GI pathogens according to age group showed the highest proportion of C. difficile in all groups, except for group 2. In group 2, rotavirus A accounted for the highest percentage (61.1%, 22/36). The incidence of GI pathogens was the highest in summer (36.1%), followed by autumn (32.7%), and winter (18.0%). The co-infection rate with two or more pathogens was 16.9% (167/991). The rates of co-infection with two or more bacteria, bacteria and viruses, and two viruses were 58.1%, 31.7%, and 10.2%, re-spectively. CONCLUSIONS: Information on the incidence and distribution of GI pathogens might be clinically useful; however, unlike the distribution of other infectious pathogens, it is necessary to consider that microorganisms identified through molecular diagnostics can be detected even in healthy people without clinical symptoms.

Fucoidan from Sargassum autumnale Inhibits Potential Inflammatory Responses via NF-κB and MAPK Pathway Suppression in Lipopolysaccharide-Induced RAW 264.7 Macrophages.

Fucoidans are sulfate-rich polysaccharides with a wide variety of beneficial biological activities. The present study aimed to highlight the anti-inflammatory activity of fucoidan from the brown seaweed Sargassum autumnale (SA) against lipopolysaccharide (LPS)-induced RAW 264.7 macrophage cells. Among the isolated fucoidan fractions, the third fraction (SAF3) showed a superior protective effect on LPS-stimulated RAW 264.7 cells. SAF3 inhibits nitric oxide (NO) production and expression of prostaglandin E-2 (PGE2) via downregulation of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX2) expression in LPS-induced RAW 26.7 cells. SAF3 treatment decreased pro-inflammatory cytokines IL-1ß, TNF-α, and IL-6 expression in LPS-induced cells. LPS stimulation activated NF-κB and MAPK signaling cascades in RAW 264.7 cells, while treatment with SAF3 suppressed them in a concentration-dependent manner. Existing outcomes confirm that SAF3 from S. autumnale possesses potent anti-inflammatory activity and exhibits good potential for application as a functional food ingredient or for the treatment of inflammation-related disorders.

Porous organic polymers for CO2 capture, separation and conversion.

Porous organic polymers (POPs) have long been considered as prime candidates for carbon dioxide (CO2) capture, separation, and conversion. Especially their permanent porosity, structural tunability, stability and relatively low cost are key factors in such considerations. Whereas heteratom-rich microporous networks as well as their amine impregnation/functionalization have been actively exploited to boost the CO2 affinity of POPs, recently, the focus has shifted to engineering the pore environment, resulting in a new generation of highly microporous POPs rich in heteroatoms and featuring abundant catalytic sites for the capture and conversion of CO2 into value-added products. In this review, we aim to provide key insights into structure-property relationships governing the separation, capture and conversion of CO2 using POPs and highlight recent advances in the field.

The Neuroprotective Effects of Dendropanax morbifera Water Extract on Scopolamine-Induced Memory Impairment in Mice.

This study investigated the neuroprotective effects of Dendropanax morbifera leaves and stems (DMLS) water extract on scopolamine (SCO)-induced memory impairment in mice. First, we conducted experiments to determine the protective effect of DMLS on neuronal cells. Treatment with DMLS showed a significant protective effect against neurotoxicity induced by Aß(25-35) or H2O2. After confirming the neuroprotective effects of DMLS, we conducted animal studies. We administered DMLS orally at concentrations of 125, 250, and 375 mg/kg for 3 weeks. In the Y-maze test, SCO decreased spontaneous alternation, but treatment with DMLS or donepezil increased spontaneous alternation. In the Morris water-maze test, the SCO-treated group showed increased platform reach time and decreased swim time on the target platform. The passive avoidance task found that DMLS ingestion increased the recognition index in short-term memory. Furthermore, memory impairment induced by SCO reduced the ability to recognize novel objects. In the Novel Object Recognition test, recognition improved with DMLS or donepezil treatment. In the mouse brain, except for the cerebellum, acetylcholinesterase activity increased in the SCO group and decreased in the DMLS and donepezil groups. We measured catalase and malondialdehyde, which are indicators of antioxidant effectiveness, and found that oxidative stress increased with SCO but was mitigated by DMLS or donepezil treatment. Thus, our findings suggest that ingestion of DMLS restored memory impairment by protecting neuronal cells from Aß(25-35) or H2O2-induced neurotoxicity, and by reducing oxidative stress.

Porous Organic Polymers for Selective Palladium Recovery and Heterogeneous Catalysis.

Palladium (Pd) recycling from waste materials is an important approach in order to meet the growing demand for Pd originating from its broad range of applications including automotive industry, electronics and catalysis. In this article, we discuss the design principles of solid-sorbents for efficient recovery of Pd from waste sources with a particular emphasis on porous organic polymers (POPs), which emerged as promising porous materials for Pd recovery due to their tunable chemical functionality, stability and porosity. We discuss the critical role of binding sites and porosity in the Pd uptake capacity, adsorption kinetics and selectivity. We also highlight the use of captured Pd within the polymer networks as heterogeneous catalysts for cross-coupling reactions.

Mixed-metal Ionothermal Synthesis of Metallophthalocyanine Covalent Organic Frameworks for CO2 Capture and Conversion.

Phthalocyanines (PCs) are intriguing building blocks owing to their stability, physicochemical and catalytic properties. Although PC-based polymers have been reported before, many suffer from relatively low stability, crystallinity, and low surface areas. Utilizing a mixed-metal salt ionothermal approach, we report the synthesis of a series of metallophthalocyanine-based covalent organic frameworks (COFs) starting from 1,2,4,5-tetracyanobenzene and 2,3,6,7-tetracyanoanthracene to form the corresponding COFs named M-pPPCs and M-anPPCs, respectively. The obtained COFs followed the Irving-Williams series in their metal contents, surface areas, and pore volume and featured excellent CO2 uptake capacities up to 7.6 mmol g-1 at 273 K, 1.1 bar. We also investigated the growth of the Co-pPPC and Co-anPPC on a highly conductive carbon nanofiber and demonstrated their high catalytic activity in the electrochemical CO2 reduction, which showed Faradaic efficiencies towards CO up to 74 % at -0.64 V vs. RHE.

Dimeric architecture of maltodextrin glucosidase (MalZ) provides insights into the substrate recognition and hydrolysis mechanism.

Maltodextrin glucosidase (MalZ) is a key enzyme in the maltose utilization pathway in Escherichia coli that liberates glucose from the reducing end of the short malto-oligosaccharides. Unlike other enzymes in the GH13_21 subfamily, the hydrolytic activity of MalZ is limited to maltodextrin rather than long starch substrates, forming various transglycosylation products in α-1,3, α-1,4 or α-1,6 linkages. The mechanism for the substrate binding and hydrolysis of this enzyme is not well understood yet. Here, we present the dimeric crystal structure of MalZ, with the N-domain generating a unique substrate binding groove. The N-domain bears CBM34 architecture and forms a part of the active site in the catalytic domain of the adjacent molecule. The groove found between the N-domain and catalytic domain from the adjacent molecule, shapes active sites suitable for short malto-oligosaccharides, but hinders long stretches of oligosaccharides. The conserved residue of E44 protrudes at subsite +2, elucidating the hydrolysis pattern of the substrate by the glucose unit from the reducing end. The structural analysis provides a molecular basis for the substrate specificity and the enzymatic property, and has potential industrial application for protein engineering.

Prevalence of Group B Streptococcus Colonization in Pregnant Women at a University Hospital in Korea.

BACKGROUND: Group B Streptococcus (GBS) colonization in pregnant women is a risk factor for causing infection in neonates; therefore, GBS screening tests are performed on them. Culture methods and molecular diagnostics are mainly performed for GBS detection; however, culture methods differ in the detection rate for GBS depending on the procedure of culture. The authors intended to confirm the difference in GBS colonization rate in the conventional culture method, enrichment culture method, and molecular genetic test as screening tests for GBS. METHODS: Duplicate vagino-rectal swabs were collected from 371 pregnant women between the 35th and 37th week of gestation; one was used for conventional culture method and the other was frozen at -80℃, followed by enrichment culture method and molecular genetic test. RESULTS: The prevalence of GBS colonization identified by conventional culture, enrichment culture, and molecular genetic test was 4.35% (17/391), 8.95% (35/391), and 22.25% (87/391), respectively. The detection rate by enrichment culture method was 2.06 times higher (17/391 vs. 35/391) than that by conventional culture method. It was identified that there was a significant difference in the detection rates of GBS between the two methods (p < 0.001). The detection rate identified in molecular genetic test was much higher at 22.25% (87/391). The concordance rate of the results from three detection methods for GBS was 80.05% (313/391). All pregnant women colonized with GBS were given intrapartum antibiotic prophylaxis using cefazolin and their neonates were confirmed not to be infected with GBS. CONCLUSIONS: Prevalence of GBS colonization in pregnant women is shown to vary depending on detection method. Particularly, it differs greatly depending on the use of enrichment media in the culture method. Therefore, it is necessary that the microbiological laboratory implements the culture method with supplementary procedures such as selective or enrichment media in order to improve the detection rate of GBS.