An exploration of meteorological effects on PM2.5 air quality in several provinces and cities in Vietnam.

Linking meteorology and air pollutants is a key challenge. The study investigated meteorological effects on PM2.5 concentration using the advanced convergent cross mapping method, utilizing hourly PM2.5 concentration and six meteorological factors across eight provinces and cities in Vietnam. Results demonstrated that temperature (ρ = 0.30) and radiation (ρ = 0.30) produced the highest effects, followed by humidity (ρ = 0.28) and wind speed (ρ = 0.24), while pressure (ρ = 0.22) and wind direction (ρ = 0.17) produced the weakest effects on PM2.5 concentration. Comparing the ρ values showed that temperature, wind speed, and wind direction had greater impacts on PM2.5 concentration during the dry season whereas radiation had a more influence during the wet season; Southern stations experienced larger meteorological effects. Temperature, humidity, pressure, and wind direction had both positive and negative influences on PM2.5 concentration, while radiation and wind speed mostly had negative influences. During PM2.5 pollution episodes, there was more contribution of meteorological effects on PM2.5 concentration indicated by ρ values. At contaminated levels, humidity (ρ = 0.45) was the most dominant factor affecting PM2.5 concentration, followed by temperature (ρ = 0.41) and radiation (ρ = 0.40). Pollution episodes were pointed out to be more prevalent under higher humidity, higher pressure, lower temperature, lower radiation, and lower wind speed. The ρ calculation also revealed that lower temperature, lower radiation, and higher humidity greatly accelerated each other under pollution episodes, further enhancing PM2.5 concentration. The findings contributed to the literature on meteorology and air pollution interaction.

A sustainable, low-cost carbonaceous hydrochar adsorbent for methylene blue adsorption derived from corncobs.

In this study, activated carbon from corncobs was successfully synthesized by hydrothermal carbonization and hydrochemical activation at low temperatures, followed by pyrolysis. A developed method of hydrochemical activation of hydrochar that uses only small amounts of chemicals is a promising approach. After activation, the activator residues in the hydrothermal product can constantly act as a chemical activator during pyrolysis to form corncob-activated carbon (AHC-KOH), which had specific surface area of 965.028 m2/g and oxygenated functional groups of 0.3780 mmol/g, 31.67 and 4 times, respectively, of those of the inactivated sample. AHC-KOH was used to study the adsorption characteristics of methylene blue (MB). The MB adsorption efficiency of AHC-KOH was the highest at 489.560 mg/g, which was considerably higher than that of activated carbons produced from other biomasses. The isotherm equilibrium and adsorbent kinetics parameters of MB adsorption on AHC-KOH were also determined using the Langmuir isotherm model (R2 = 0.99) and pseudo-second-order kinetic model (R2 > 0.99). Thus, the results indicate that an inexpensive adsorbent produced from corncobs using the above method is a promising material for wastewater treatment.

Live birth after in vitro maturation in women with gonadotropin resistance ovary syndrome: report of two cases.

PURPOSE: Gonadotropin-resistant ovary syndrome (GROS) is a rare endocrine disorder that causes hypergonadotropic hypogonadism, amenorrhea, and infertility. This study reports live birth in two women with GROS who underwent fertility treatment with in vitro maturation (IVM). METHODS: Both patients had primary infertility, amenorrhea (primary and secondary), typical secondary sexual characters, elevated gonadotropin levels, normal ovarian reserve, normal chromosomal characteristics, and previous nonresponsiveness gonadotropin stimulations. One patient had polymorphism of the follicle-stimulating hormone receptor, which is a predictor of poor ovarian response. Given unresponsiveness to exogenous gonadotropin stimulations, IVM with human chorionic gonadotropin priming (hCG-IVM) was performed in both patients. All transferrable embryos were vitrified. RESULTS: Both patients achieved pregnancy after their first frozen embryos transfer, and each delivered a healthy baby boy. CONCLUSIONS: These results suggest that IVM should be a first-line therapeutic option for patients with GROS.

Structural Basis of CYRI-B Direct Competition with Scar/WAVE Complex for Rac1.

Rac1 is a major regulator of actin dynamics, with GTP-bound Rac1 promoting actin assembly via the Scar/WAVE complex. CYRI competes with Scar/WAVE for interaction with Rac1 in a feedback loop regulating actin dynamics. Here, we reveal the nature of the CYRI-Rac1 interaction, through crystal structures of CYRI-B lacking the N-terminal helix (CYRI-BΔN) and the CYRI-BΔN:Rac1Q61L complex, providing the molecular basis for CYRI-B regulation of the Scar/WAVE complex. We reveal CYRI-B as having two subdomains - an N-terminal Rac1 binding subdomain with a unique Rac1-effector interface and a C-terminal Ratchet subdomain that undergoes conformational changes induced by Rac1 binding. Finally, we show that the CYRI protein family, CYRI-A and CYRI-B can produce an autoinhibited hetero- or homodimers, adding an additional layer of regulation to Rac1 signaling.

CYRI-A limits invasive migration through macropinosome formation and integrin uptake regulation.

The Scar/WAVE complex drives actin nucleation during cell migration. Interestingly, the same complex is important in forming membrane ruffles during macropinocytosis, a process mediating nutrient uptake and membrane receptor trafficking. Mammalian CYRI-B is a recently described negative regulator of the Scar/WAVE complex by RAC1 sequestration, but its other paralogue, CYRI-A, has not been characterized. Here, we implicate CYRI-A as a key regulator of macropinosome formation and integrin internalization. We find that CYRI-A is transiently recruited to nascent macropinosomes, dependent on PI3K and RAC1 activity. CYRI-A recruitment precedes RAB5A recruitment but follows sharply after RAC1 and actin signaling, consistent with it being a local inhibitor of actin polymerization. Depletion of both CYRI-A and -B results in enhanced surface expression of the α5ß1 integrin via reduced internalization. CYRI depletion enhanced migration, invasion, and anchorage-independent growth in 3D. Thus, CYRI-A is a dynamic regulator of macropinocytosis, functioning together with CYRI-B to regulate integrin trafficking.

Adsorption isotherms and kinetic modeling of methylene blue dye onto a carbonaceous hydrochar adsorbent derived from coffee husk waste.

In this study, activated carbon in the form of carbonaceous hydrochar adsorbents with highly functionalized surface-active sites were produced from coffee husk waste via hydrothermal carbonization under low-temperature conditions (180 °C) and subsequent chemical activation. Thereafter, the hydrochars were characterized using diverse analytical techniques, and batch experiments of methylene blue (MB) adsorption were performed under various operating conditions. The results indicated that the activated hydrochar (AH) had a larger specific surface area (862.2 m2 g-1) compared to that of its carbonaceous precursor (33.7 m2 g-1). The maximum MB sorption capacity of the hydrochar activated with potassium hydroxide was extremely high (415.8 mg g-1 at 30 °C). In addition, adsorption isotherms and kinetics were studied using experimental data fitting to further understand and describe the dynamic equilibrium, dynamic kinetics, and mechanism of MB adsorption onto the prepared hydrochars. As compared to the Freundlich isotherm model, the Langmuir isotherm model provided a better fit with the experimental data exhibiting a maximum monolayer adsorption capacity of 418.78 mg g-1. The linear pseudo-second-order kinetic model was found to be suitable for describing the adsorptive kinetics of the hydrochar. The results demonstrated the immense potential of coffee husk waste to produce activated carbon as an alternative green hydrochar that can be applied to dye removal from wastewater as well as improvement of waste management.

Evaluation of Roots and Canal Systems of Mandibular First Molars in a Vietnamese Subpopulation Using Cone-Beam Computed Tomography.

OBJECTIVES: The aim of this study is to determine the prevalence of the first lower molars that have two roots or three roots and the number of the root canals of the mandibular first molars in the Vietnamese subpopulation using cone-beam computed tomography (CBCT). MATERIALS AND METHODS: The study was conducted on 166 patients who had CBCT as indicated by dentists in Nguyen Trai Dental CT Center, Ho Chi Minh City using the Picasso Trio (Ewoo Vatech, Korea). The number of root canals of the first lower molars was examined by moving cross-sectional slices from the pulpal floor to the apex. The orifices, middle thirds, and apical thirds of the canals of the first lower molar were observed, and the root canals of each root of the mandibular first molars were observed in three planes. RESULTS: The prevalence of two, three, and four root canals of the mandibular first molars was 4.5%, 66.8%, and 28.9%, respectively. For the distal roots of these molars, a classification of Vertucci type I was the most common at a rate of 80.8%-97.6%. Whenever these teeth had three roots, a Vertucci type I was the classification of 100% of distolingual roots. CONCLUSION: Majority of the mandibular first molars has two roots and three canals. CBCT is appropriate equipment useful in investigating the complex root canal morphology of human teeth.

Anti-influenza sesquiterpene from the roots of Reynoutria japonica.

One new flavonol glycoside, 4'-O-methylmyricitrin 3'-O-beta-D-glucopyranoside (1), one new sesquiterpene, reynoudiol (11), as well as the 12 known compounds (2-10, 12-14) quercetin 3-O-methyl ether (2), quercitrin (3), isorhamnetin 3-alpha-L-rhamnopyranoside (4), tamarixetin 3-alpha-L-rhamnopyranoside (5), myricitrin (6), 4'-O-methylmyricitrin (7), isorhamnetin 3-O-beta-D-xylopyranosyl (1-2)-O-beta- D-glucopyranoside (8), isorhamnetin 3-O-beta- D-apiofuranosyl(1-2)-O-beta- D-glucopyranoside (9), (+)-catechin (10), 7-drimene-3,11,12-triol (12), clovane-2 beta,9 alpha-diol (13), and a-cadinol (14), were isolated from the methanol extract of Reynoutria japonica roots. Based on in vitro screening of the anti-influenza activity of the isolated compounds, reynoudiol showed significantly higher activity than that of oseltamivir phosphate at the same concentration, and did not induce any detectable cytopathic effect in MDCK cells. The CC50 of reynoudiol was above 50 micro M and could inhibit influenza virus infection with an IC50 of 0.29 +/- 0.01 microM. The therapeutic index (TI) of reynoudiol against influenza infection was 172.4, and thus, this compound can be potentially used to treat oseltamivir-resistant influenza virus infection.

New isoflavone glycosides from the stems of Dalbergia vietnamensis.

Two new isoflavone glycosides, dalspinosin 7-O-beta-D-apiofuranosyl-(1-->6)-beta-D-glucopyranoside (1) and caviunin 7-O-(5-O-trans-p-coumaroyl)-beta-D-apiofuranosyl-(1-->6)-beta-D-glucopyranoside (2), and two known compounds, caviunin 7-O-beta-D-apiofuranosyl-(1-->6)-beta-D-glucopyranoside (3) and caviunin (4) were isolated from the stems of Dalbergia vietnamensis. Their structures were determined by the combination of spectroscopic and chemical methods, including 1D- and 2D-NMR spectroscopy, as well as by comparing with the NMR data reported in the literature.

New butenolide and pentenolide from Dysidea cinerea.

Two new butenolide and pentenolide derivatives, dysideolides A-B, were isolated from the marine sponge Dysidea cinerea. Their structures were determined by the combination of spectroscopic and chemical methods, including 1D- and 2D-NMR spectroscopy, and CD spectra, as well as by comparing with the NMR data reported in the literature.