Efficient biofuel production by MTV-UiO-66 based catalysts

In this study, highly defected and functionalized metal-organic framework (MOF) structures are developed and exploited as catalysts for an esterification reaction for biofuel production. Two systems of multivariate UiO-66 series, namely MTV-UiO-66(COOH)2 and MTV-UiO-66(OH)2 incorporating dicarboxylate and dihydroxy groups, respectively, along with the single component structures, are thus explored for butyl butyrate production. Ratios of functionalized linkers to terephthalic acid are varied and a modulation synthesis approach is employed allowing for high levels of structural defects. The synthesized MOF structures are fully characterized using Powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), proton nuclear magnetic resonance (1H NMR), Brunauer–Emmett–Teller (BET), and scanning electron microscopy (SEM), and the results confirmed the homogeneous incorporation of the functionalized linkers in the structures. The combination of multivariate approach along with modulation synthesis yields structures with catalytic activity higher than those of highly defective fully functionalized structures and close to the homogeneous conventional catalyst used in esterification reactions. Moreover, the ratio of functionalized linkers to terephthalic acid is shown to be very important since not all MTV-UiO-66 performed better than the single-component structure which can be attributed to a combination of factors related to the density of active sites and their accessibility. The most active MTV-UiO-66(OH)2 member, incorporating 52% of functionalized linkers, a defects number of 1.9, and a surface area of 761 m2/g, yielded 92% conversion to butyl butyrate, compared to 95% for H2SO4, and its activity and stability is maintained over 4 consecutive cycles. Furthermore, by using the data of 33 different UiO-66 based catalysts for butyl butyrate production, a weighted linear regression model is suggested to predict the conversion based on the parameters that are concluded to mostly govern the catalytic activity of MOF catalysts. These parameters include the surface area, the catalytic loading, the defects number, and the level of incorporation of BDC, and the functionalized linkers. The weights calculated for each of these parameters indicate that there is a more pronounced effect of active sites density on the conversion when compared to the surface area or the catalyst loading. These conclusions help pave the way for the engineering of MOF-based catalysts in the path of bridging the gap between homogeneous and heterogeneous catalysis for efficient biofuel production

MOESM6 of Designing, construction and characterization of genetically encoded FRET-based nanosensor for real time monitoring of lysine flux in living cells

Additional file 6: Figure S6. A. Nucleotide sequences of construct with His-tag (green)- CFP (cyan) –LAO (grey) –YFP (yellow). B. Amino acid sequence of FLIPK construct

Metal–Organic Framework-74 for Ultratrace Arsenic Removal from Water: Experimental and Density Functional Theory Studies

This study investigates and compares arsenic, As­(V), removal from aqueous media using the water-stable zinc metal–organic frameworks (Zn-MOF-74) prepared via room-temperature precipitation (RT-Zn-MOF-74) and a solvothermal procedure (HT-Zn-MOF-74). The Zn-MOF-74 crystals possess average particle sizes of 66 nm and 144 μm for RT-Zn-MOF-74 and HT-Zn-MOF-74, respectively. Moreover, nanosized RT-Zn-MOF-74 exhibited a superior performance to HT-Zn-MOF-74. While the Brunauer–Emmett–Teller surface area of RT-Zn-MOF-74 was smaller than that of HT-Zn-MOF-74, higher adsorption uptake took place on the room-temperature-synthesized ones because of their small particle size and better dispersion. Adsorption isotherm studies showed that the Langmuir isotherm was effective for the adsorption of As­(V) onto RT-Zn-MOF-74 and HT-Zn-MOF-74 with maximum adsorption uptake (<i>q</i>_max) values of 99.0 and 48.7 mg g^–1, respectively. These values exceed most reported maximum adsorption capacities at neutral pH. The thermodynamics of adsorption revealed a spontaneous endothermic process that is due to the substitution of adsorbed water molecules by arsenate in the pores of the MOF crystal. This was further investigated using plane-wave density functional theory calculations. This study constitutes direct evidence for the importance of tuning the size of the MOF crystals to enhance their properties

Secondary infection rate of COVID-19 and its association with selected variables in households of CRHSP, Ballabgarh, Haryana, 2021.

Secondary infection rate of COVID-19 and its association with selected variables in households of CRHSP, Ballabgarh, Haryana, 2021.</p

Risk factors associated with secondary infection rate of COVID-19 in households of CRHSP, Ballabgarh, Haryana, 2021.

Risk factors associated with secondary infection rate of COVID-19 in households of CRHSP, Ballabgarh, Haryana, 2021.</p

Demographic and baseline characteristics of index cases, household contacts, and secondary cases of COVID in CRHSP, Ballabgarh, Haryana, 2021.

Demographic and baseline characteristics of index cases, household contacts, and secondary cases of COVID in CRHSP, Ballabgarh, Haryana, 2021.</p

Human Circulating Antibody-Producing B Cell as a Predictive Measure of Mucosal Immunity to Poliovirus

<p><b>a:</b> Proportion of subjects excreting virus after booster vaccination with OPV and IPV vaccines by intervention group and poliovirus serotype. PV1: Poliovirus type 1; PV2: Poliovirus type 2; PV3: Poliovirus type 3; IPV: Inactivated Polio Vaccine; bOPV = bivalent Oral Polio Vaccine. <b>b:</b> Proportion of subjects with immune response after booster vaccination with OPV and IPV vaccines by intervention group and poliovirus serotype.</p

CONSORT flow diagram of included subjects.

<p>bOPV = bivalent Oral Polio Vaccine; IPV = Inactivated Polio Vaccine; ELISPOT = Enzyme-Linked ImmunoSpot.</p

Measles Case Fatality Rate in Bihar, India, 2011–12

<div><p>Background</p><p>Updated estimates of measles case fatality rates (CFR) are critical for monitoring progress towards measles elimination goals. India accounted for 36% of total measles deaths occurred globally in 2011. We conducted a retrospective cohort study to estimate measles CFR and identify the risk factors for measles death in Bihar–one of the north Indian states historically known for its low vaccination coverage.</p><p>Methods</p><p>We systematically selected 16 of the 31 laboratory-confirmed measles outbreaks occurring in Bihar during 1 October 2011 to 30 April 2012. All households of the villages/urban localities affected by these outbreaks were visited to identify measles cases and deaths. We calculated CFR and used multivariate analysis to identify risk factors for measles death.</p><p>Results</p><p>The survey found 3670 measles cases and 28 deaths (CFR: 0.78, 95% confidence interval: 0.47–1.30). CFR was higher among under-five children (1.22%) and children belonging to scheduled castes/tribes (SC/ST, 1.72%). On multivariate analysis, independent risk factors associated with measles death were age <5 years, SC/ST status and non-administration of vitamin A during illness. Outbreaks with longer interval between the occurrence of first case and notification of the outbreak also had a higher rate of deaths.</p><p>Conclusions</p><p>Measles CFR in Bihar was low. To further reduce case fatality, health authorities need to ensure that SC/ST are targeted by the immunization programme and that outbreak investigations target for vitamin A treatment of cases in high risk groups such as SC/ST and young children and ensure regular visits by health-workers in affected villages to administer vitamin A to new cases.</p></div

Measles case fatality rate among SC/ST and G/OBC cases stratified by age group and vitamin A administration, Bihar, India.

<p>Measles case fatality rate among SC/ST and G/OBC cases stratified by age group and vitamin A administration, Bihar, India.</p