462 research outputs found
Selective cyclodimerization of epichlorohydrin to dioxane derivatives over MOFs
Glycerol can be converted to valuable products such as epichlorohydrin which is an important intermediate applied in various industries. For example, dioxane derivatives, which are important pharmaceuticals, can be obtained from epichlorohydrin. In the present study, ZIF-8, ZIF-67, MIL-100, and UiO-66 were applied for the direct cyclodimerization of epichlorohydrin. These MOFs were selected because they were already applied as active catalysts in ring opening of epoxides. Among them, ZIF-8 showed the highest activity and selectivity in the absence of any solvent or co-catalyst. Using ZIF-8 as a catalyst, the cyclodimer product (1,4-dioxane 2,5-bis-chloromethyl) was obtained in a yield of about 70% which was significantly superior to previous homo or heterogeneous catalysts for this reaction. Due to ZIF-8 structure and the proposed mechanism, the cyclodimerization reaction catalyzed either by the defects in the structure and/or on the surface. Furthermore, acidic-basic characteristics were also in play. The NH3 and CO2 temperature-programed desorption technique were utilized to identify the active sites and thereby reaction mechanism. Moreover, because of similar properties of ZIF-8 to zeolites, the activity of commercial ZSM-5 for the same reaction was also investigated in this work
Photooxidation of a twisted isoquinolinone
Understanding the oxidation mechanism and positions of twistacenes and twistheteroacenes under ambient conditions is very important because such knowledge can guide us to design and synthesize novel, larger stable analogues. Herein, we demonstrated for the first time that a twisted isoquinolinone can decompose under oxygen and light at room temperature. The as‐decomposed product 1 was fully characterized through conventional methods as well as single‐crystal structure analysis. Moreover, the physical properties of the as‐obtained product were carefully investigated and the possible formation mechanism was proposed
Cost comparison of commonly used antidepressant drugs with drug price control order in India
Background: Price of a drug is an important factor for compliance to the treatment. So, to overcome the high prices of drugs, National Pharmaceutical Pricing Authority (NPPA) under government of India has issued Drug Price Control Order (DPCO) list containing commonly used drugs. Pharmaceutical companies can be punished if they keep their prices higher than the ceiling price mentioned in the DPCO. To find out the price variations of commonly used antidepressant drugs included in DPCO list of 29th April 2019.Methods: A list of all oral antidepressant drugs included in DPCO of 29th April 2019 and available in Indian market was procured from medguide India. Analysis of number of total brands following as well as not following DPCO ceiling price was done.Results: Author found 17 formulations of four antidepressant drugs included in DPCO. Total 556 brands found out of which 84.6% were following the DPCO and 15.4% of brands prices were higher than the ceiling price of DPCO.Conclusions: Though large number of companies are following the DPCO but still strict regulation is needed to further increase the compliance of guidelines
Alcohol and Smoking Mediated Modulations in Adaptive Immunity in Pancreatitis
Pancreatitis is a condition of pancreatic inflammation driven by injury to the pancreatic parenchyma. The extent of acinar insult, intensity, and type of immune response determines the severity of the disease. Smoking, alcohol and autoimmune pancreatitis are some of the predominant risk factors that increase the risk of pancreatitis by differentially influencing the adaptive immune system. The overall decrease in peripheral lymphocyte (T-, B- and (natural killer T-) NKT-cell) count and increased infiltration into the damaged pancreatic tissue highlight the contribution of adaptive immunity in the disease pathology. Smoking and alcohol modulate the responsiveness and apoptosis of T- and B-cells during pancreatic insult. Acute pancreatitis worsens with smoking and alcohol, leading to the development of systemic inflammatory response syndrome and compensatory anti-inflammatory response syndrome, suggesting the critical role of adaptive immunity in fatal outcomes such as multiple organ dysfunction. The presence of CD4+ and CD8+ T-lymphocytes and perforin-expressing cells in the fibrotic tissue in chronic pancreatitis modulate the severity of the disease. Due to their important role in altering the severity of the disease, attempts to target adaptive immune mediators will be critical for the development of novel therapeutic interventions
A multi-step solvent-free mechanochemical route to indium(III) complexes
La Química mecánica está bien establecida en la fase sólida de síntesis de materiales inorgánicos, pero rara vez ha sido empleada para la síntesis molecular. En los últimos años, ha habido interés en los nacientes métodos sintéticos "más verde" con menos solvente, rendimientos más altos y tiempos de reacción más cortos, todo lo cual es especialmente atractivo para los productos de química fina y los catalizadores inorgánicos de la industria. Aquí, demostramos que el grupo principal de complejo indio (III) ligado con bis(imino)acenafteno (bian) son fácilmente accesibles a través de un enfoque de molienda de química mecánica. La metodología sintética reporta, y no sólo evita, la utilización de grandes cantidades de disolventes y reactivos para metales de transición ligando la síntesis, pero también reduce drásticamente los tiempos de reacción. Estos nuevos grupos, principalmente complejos, muestran el potencial de ser reducidos al complejo indio (I), que pueden ser empleadas como en productos fotosensibles en catálisis orgánicas cataliza y materiales funcionales.Mechanochemistry is well-established in the solid-phase synthesis of inorganic materials but has rarely been employed for molecular syntheses. In recent years, there has been nascent interest in ‘greener’ synthetic methods with less solvent, higher yields, and shorter reaction times being especially appealing to the fine chemicals and inorganic catalyst industries. Herein, we demonstrate that main-group indium(III) complexes featuring bis(imino)acenaphthene (BIAN) ligands are readily accessible through a mechanochemical milling approach. The synthetic methodology reported herein not only bypasses the use of large solvent quantities and transition metal reagents for ligand synthesis, but also reduces reaction times dramatically. These new main-group complexes exhibit the potential to be reduced to indium(I) compounds, which may be employed as photosensitizers in organic catalyses and functional materials.Trabajo financiado por:
Nanyang Technological University (Singapur). Ayuda M4080552, para Felipe García García
Ministry of Education (Singapur). Ayuda nivel 1. M4011441, para Felipe García García
Nanyang Technological University (Singapur). Ayuda M4081012, para Han Sen Soo
Ministry of Education (Singapur). Ayuda nivel 1M4011144, para Han Sen Soo
Nanyang. Ayuda Profesor Ayudante M4081154, para Han Sen SoopeerReviewe
Implikasi Putusan Mahkamah Konstitusi Nomor 11-017/puu-i/2003 terhadap Perlindungan Hukum Hak Dipilih
Paper that had the title: "Juridical implications of the Constitutional Court Decision Number 011-017/PUU-I/2003 on the Legal Protection for the Rights to be Eelected." This explores two issues: 1) how the legal protection of the settings selected in the state system of Indonesia ; 2) what are juridical implications of the Constitutional Court Decision Number 011-017/PUU-I/2003 on the legal protection for the rights to be elected. To solve both problems, this paper uses normative legal research methods. Approach being used is the statute approach, case approach, and a conceptual approach. Further legal materials collected were identified and analyzed using descriptive analysis techniques. Legal protection for the right to be elected in the state system of Indonesia can be traced from the 1945 opening, the articles in the body of the 1945 Constitution, Article 27 paragraph (1), Article 28D (1) and paragraph (3) and Article 28 paragraph (3) 1945 Second Amendment, MPR Decree Number XVII/MPR/1998, Article 43 of Law Number 39 of 1999, Article 21 of the Universal Declaration of Human Rights, and Article 25 of the International Covenant on Civil and Political Rights. Discussion of the juridical implications of the Constitutional Court Decision Number 011-017/PUU-I/2003 on the legal protection for the rights to be elected have been included: a) only on the juridical implications of representative institutions no longer marked with specified requirements as stipulated in Article 60 letter g of Law Number 12 Year 2003 in Law Number 10 Year 2008; b) juridical implications of the political field for the right to be elected is the absence of any discriminatory treatment in legislative product formed by the House of Representatives and the President as well as products of other legislation forward
GW190412: Observation of a Binary-Black-Hole Coalescence with Asymmetric Masses
We report the observation of gravitational waves from a binary-black-hole coalescence during the first two weeks of LIGO’s and Virgo’s third observing run. The signal was recorded on April 12, 2019 at 05∶30∶44 UTC with a network signal-to-noise ratio of 19. The binary is different from observations during the first two observing runs most notably due to its asymmetric masses: a ∼30 M_⊙ black hole merged with a ∼8 M_⊙ black hole companion. The more massive black hole rotated with a dimensionless spin magnitude between 0.22 and 0.60 (90% probability). Asymmetric systems are predicted to emit gravitational waves with stronger contributions from higher multipoles, and indeed we find strong evidence for gravitational radiation beyond the leading quadrupolar order in the observed signal. A suite of tests performed on GW190412 indicates consistency with Einstein’s general theory of relativity. While the mass ratio of this system differs from all previous detections, we show that it is consistent with the population model of stellar binary black holes inferred from the first two observing runs
The population of merging compact binaries inferred using gravitational waves through GWTC-3
We report on the population properties of 76 compact binary mergers detected with gravitational waves below a false alarm rate of 1 per year through GWTC-3. The catalog contains three classes of binary mergers: BBH, BNS, and NSBH mergers. We infer the BNS merger rate to be between 10 and 1700 and the NSBH merger rate to be between 7.8 and 140 , assuming a constant rate density versus comoving volume and taking the union of 90% credible intervals for methods used in this work. Accounting for the BBH merger rate to evolve with redshift, we find the BBH merger rate to be between 17.9 and 44 at a fiducial redshift (z=0.2). We obtain a broad neutron star mass distribution extending from to . We can confidently identify a rapid decrease in merger rate versus component mass between neutron star-like masses and black-hole-like masses, but there is no evidence that the merger rate increases again before 10 . We also find the BBH mass distribution has localized over- and under-densities relative to a power law distribution. While we continue to find the mass distribution of a binary's more massive component strongly decreases as a function of primary mass, we observe no evidence of a strongly suppressed merger rate above . The rate of BBH mergers is observed to increase with redshift at a rate proportional to with for . Observed black hole spins are small, with half of spin magnitudes below . We observe evidence of negative aligned spins in the population, and an increase in spin magnitude for systems with more unequal mass ratio
Diving below the spin-down limit:constraints on gravitational waves from the energetic young pulsar PSR J0537-6910
We present a search for continuous gravitational-wave signals from the young, energetic X-ray pulsar PSR J0537-6910 using data from the second and third observing runs of LIGO and Virgo. The search is enabled by a contemporaneous timing ephemeris obtained using NICER data. The NICER ephemeris has also been extended through 2020 October and includes three new glitches. PSR J0537-6910 has the largest spin-down luminosity of any pulsar and is highly active with regards to glitches. Analyses of its long-term and inter-glitch braking indices provided intriguing evidence that its spin-down energy budget may include gravitational-wave emission from a time-varying mass quadrupole moment. Its 62 Hz rotation frequency also puts its possible gravitational-wave emission in the most sensitive band of LIGO/Virgo detectors. Motivated by these considerations, we search for gravitational-wave emission at both once and twice the rotation frequency. We find no signal, however, and report our upper limits. Assuming a rigidly rotating triaxial star, our constraints reach below the gravitational-wave spin-down limit for this star for the first time by more than a factor of two and limit gravitational waves from the l = m = 2 mode to account for less than 14% of the spin-down energy budget. The fiducial equatorial ellipticity is limited to less than about 3 x 10⁻⁵, which is the third best constraint for any young pulsar
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