RESUMEN

This work explores a new application of titanium nitride nanoparticles (TiN NPs) as efficient photothermal materials in enhancing the greenhouse effect. We demonstrate that a simple greenhouse using TiN NPs-embedded black paint boasts several advantages in solar drying technology, which are indicated by the drying of red chilli. In particular, the greenhouse using TiN NPs significantly improves the drying efficiency, which reduces the mass of red chilli by approximately four times and results in dried chilli with a moisture content of 10% within two days. In addition, by conducting long experiments in various environments, we found that the relative humidity can have a predominant role over the temperature in the solar drying of red chilli and observed that the re-adsorption of moisture can take place during the drying process, which prolongs the drying time and reduces the quality of the dried products.

RESUMEN

Gastrointestinal bleeding due to hemobilia is a rare condition but can be very serious, even life-threatening. The main causes of biliary bleeding are invasive procedures in treatment, trauma, or malignant diseases. Chronic obstruction of the biliary tract can cause inflammation, erosion, and leakage of adjacent vascular structures and lead to pseudoaneurysm or hemorrhage, but this is very rare. In this article, we present a clinical case of upper gastrointestinal bleeding due to a pseudoaneurysm of the hepatic artery believed to have formed due to chronic cholangitis. An 81-year-old female patient with a medical history of chronic cholangitis was admitted to the hospital with recurrent inflammation accompanied by progressive upper gastrointestinal bleeding, potentially life-threatening. Ultrasound images and blood tests confirmed that the patient had anemia and cholangitis caused by stones. Gastrointestinal endoscopy showed bleeding suspected to be from the biliary tract. Hepatobiliary computed tomography confirmed that the common hepatic artery pseudoaneurysm located at the upper end of the common bile duct had active bleeding.

RESUMEN

Nanostructures of titanium nitride (TiN) have recently been considered as a new class of plasmonic materials that have been utilized in many solar energy applications. This work presents the synthesis of a novel nanostructure of TiN that has a nanodonut shape from natural ilmenite ore using a low-cost and bulk method. The TiN nanodonuts exhibit strong and spectrally broad localized surface plasmon resonance absorption in the visible region centered at 560 nm, which is well suited for thermoplasmonic applications as a nanoscale heat source. The heat generation is investigated by water evaporation experiments under simulated solar light, demonstrating excellent solar light harvesting performance of the nanodonut structure.

RESUMEN

A family of closo-carborane-appended luminophores (closo-OXD1-2 and closo-DPS1-2) in which 2-R-o-carboranes (R = H, Me) are attached to the diphenyl-1,3,4-oxadiazole (OXD) or diphenyl-sulfone (DPS) acceptor groups were prepared and characterized. Deboronation of the closo-carborane cage produced the corresponding nido-carboranyl luminophores (nido-OXD1-2 and nido-DPS1-2). Whereas the closo-compounds were poorly emissive in THF (ΦPL < 0.01), the nido-luminophores exhibited an intense fluorescence with good quantum yields (ΦPL = 0.1-0.45). Electrochemical studies showed that while the closo-OXD and -DPS compounds displayed only carborane-centred, quasi-reversible reduction, the nido-compounds exhibited the typical features for nido-carborane-centred, irreversible oxidation and acceptor-centred, reversible reduction. Theoretical studies suggested that while the 1ππ* state of closo-compounds is nonemissive due to the contribution of closo-carborane to the LUMO in the S1 excited state, the intramolecular charge transfer (ICT) state from the nido-carborane to acceptor moieties in nido-compounds leads to an efficient fluorescence. Finally, THF solutions of closo-OXD1 and -DPS1 showed strong fluorescence upon the addition of fluoride anions under mild heating, but were intact to other anions, including cyanide, allowing the selective OFF-ON fluorescence sensing of fluoride.

RESUMEN

An approach to the design of nido-carborane-based luminescent compounds that can exhibit thermally activated delayed fluorescence (TADF) is proposed. 7,8-Dicarba-nido-undecaboranes (nido-carboranes) having various 8-R groups (R=H, Me, i-Pr, Ph) are appended to the meta or para position of the phenyl ring of the dimesitylphenylborane (PhBMes2 ) acceptor, forming donor-acceptor compounds (nido-m1-m4 and nido-p1-p4). The bulky 8-R group and meta substitution of the nido-carborane are essential to attain a highly twisted arrangement between the donor and acceptor moieties, leading to a very small energy splitting between the singlet and triplet excited states (ΔEST <0.05 eV for nido-m2, -m3, and -p3). These compounds exhibit efficient TADF with microsecond-range lifetimes. In particular, nido-m2 and -m3 display aggregation-induced emission (AIE) with TADF properties.

RESUMEN

BACKGROUND: Drug resistant tuberculosis (TB) is increasing in prevalence worldwide. Treatment failure and relapse is known to be high for patients with isoniazid resistant TB treated with standard first line regimens. However, risk factors for unfavourable outcomes and the optimal treatment regimen for isoniazid resistant TB are unknown. This cohort study was conducted when Vietnam used the eight month first line treatment regimen and examined risk factors for failure/relapse among patients with isoniazid resistant TB. METHODS: Between December 2008 and June 2011 2090 consecutive HIV-negative adults (≥18 years of age) with new smear positive pulmonary TB presenting at participating district TB units in Ho Chi Minh City were recruited. Participants with isoniazid resistant TB identified by Microscopic Observation Drug Susceptibility (MODS) had extended follow-up for 2 years with mycobacterial culture to test for relapse. MGIT drug susceptibility testing confirmed 239 participants with isoniazid resistant, rifampicin susceptible TB. Bacterial and demographic factors were analysed for association with treatment failure and relapse. RESULTS: Using only routine programmatic sputum smear microscopy for assessment, (months 2, 5 and 8) 30/239 (12.6%) had an unfavourable outcome by WHO criteria. Thirty-nine patients were additionally detected with unfavourable outcomes during 2 year follow up, giving a total of 69/239 (28.9%) of isoniazid (INH) resistant cases with unfavourable outcome by 2 years of follow-up. Beijing lineage was the only factor significantly associated with unfavourable outcome among INH-resistant TB cases during 2 years of follow-up. (adjusted OR = 3.16 [1.54-6.47], P = 0.002). CONCLUSION: One third of isoniazid resistant TB cases suffered failure/relapse within 2 years under the old eight month regimen. Over half of these cases were not identified by standard WHO recommended treatment monitoring. Intensified research on early identification and optimal regimens for isoniazid resistant TB is needed. Infection with Beijing genotype of TB is a significant risk factor for bacterial persistence on treatment resulting in failure/relapse within 2 years. The underlying mechanism of increased tolerance for standard drug regimens in Beijing genotype strains remains unknown.

Asunto(s)

Antituberculosos/uso terapéutico , Isoniazida/uso terapéutico , Mycobacterium tuberculosis/efectos de los fármacos , Tuberculosis Resistente a Múltiples Medicamentos/tratamiento farmacológico , Tuberculosis Pulmonar/tratamiento farmacológico , Adolescente , Adulto , Estudios de Cohortes , Femenino , Humanos , Masculino , Persona de Mediana Edad , Mycobacterium tuberculosis/genética , Recurrencia , Rifampin/uso terapéutico , Factores de Riesgo , Esputo/microbiología , Insuficiencia del Tratamiento , Vietnam , Adulto Joven

RESUMEN

A series of mono-, di-, and tri-phosphine oxide substituted triarylboranes, Mes2BAr (1), MesBAr2 (2), and BAr3 (3) (Ar = 4-(Ph2PO)-2,6-Me2-C6H2) were prepared to investigate the effect of a phosphine oxide group (Ph2PO) on Lewis acidity enhancement of triarylboranes. The X-ray crystal structure of 3 revealed peripheral decoration of Ph2PO groups with a C3-axis perpendicular to the trigonal boron center. UV/Vis absorption and PL spectra indicated a significant contribution of π(Mes or phenylene) → pπ(B) charge transfer in the lower-energy electronic transition. The reduction potential measured by cyclic voltammetry showed apparent LUMO stabilization by introduction of phosphine oxide groups, the extent of which gradually increased with the increasing number of phosphine oxide groups. Lewis acidity enhancement was also supported by the gradual increase in fluoride ion affinity in the order 3 > 2 > 1. Theoretical calculations suggest that introduction of a Ph2PO group into a triarylborane significantly enhances the Lewis acidity of the boron center via an inductive electron-withdrawing effect and this effect is additive for multiple phosphine oxide groups.