Efficient and chemoselective imine synthesis catalyzed by a well-defined PN3-manganese(II) pincer system.

The highly efficient reductive amination of aldehydes with ammonia (NH3) and hydrogen (H2) to form secondary imines is described, as well as the dehydrogenative homocoupling of benzyl amines. Using an air-stable, well-defined PN3-manganese(II) pincer complex as a catalyst precursor, various aldehydes are easily converted directly into secondary imines using NH3 as a nitrogen source under H2 in a one-pot reaction. Importantly, the same catalyst facilitates the dehydrogenative homocoupling of various benzylamines, exclusively forming imine products. These reactions are conducted under very mild conditions, without the addition of any additives, yielding excellent selectivities and high yields of secondary imines in a green manner by minimizing wastes.

Craniocervical Tetanus: A Practical Consideration During Work-up of Acute-Onset Trismus.

This clinical record revisits the classical and pathognomonic features of craniocervical tetanus in a 65-year-old farmer who presented with acute-onset trismus, multiple cranial nerve pareses (III, IX, and X), risus sardonicus, and spasm of the head-neck musculature. This paper explores the relevant literature and presents a brief pictorial analysis of the global epidemiologic data. With most countries successfully adopting the maternal and neonatal tetanus elimination (MNTE) program, the incidence and mortality of tetanus across age groups have sharply reduced in high-income and most middle-income nations. In adults, tetanus is now encountered in specialized situations like waning immunity and incomplete vaccination, in the resource-poor and low-income nations, in countries achieving MNTE recently, and as cluster cases in the aftermath of natural disasters involving human settlements. Therefore, present-day practicing otolaryngologists and residents who have limited exposure to the tell-tale clinical features of craniocervical tetanus should consider it during work-up of acute-onset trismus in adults in susceptible situations and with a conducive background. The clinical spectrum of craniocervical tetanus as depicted in this report, including the demonstration of the pathognomonic positive spatula test, provides valuable learning points for otolaryngologists in this regard.

Should developing countries ban dual practice by physicians? Analysis under mixed hospital competition.

Dual practice, where physicians work both in public and private hospitals, is a widely observed phenomenon, particularly in developing countries. This paper studies a multi-stage game where hospitals compete for physicians as well as patients and, the service provided by physicians endogenously depends on the competitive setting in which hospitals operate. Specifically, we examine the impact of allowing dual practice on hospital payoffs, physician's service and societal welfare. We find that dual practice is socially desirable, since it softens the competition for physician's exclusive service while also increasing the amount of their service. However, if the degree of competition between the hospitals is significant, dual practice may not yield the highest payoffs for both public and private hospitals.

Change in the H-V Interval Without a Change in QRS Morphology During Atrial Pacing in a Case of Wolff-Parkinson-White Syndrome-What is the Mechanism?

In the background of an accessory pathway (AP), the H-V interval can vary during atrial/coronary sinus pacing, but only with a concomitant change in the QRS morphology and the degree of pre-excitation. In an interesting case of a 62-year-old woman, the H-V interval varied during coronary sinus pacing despite a fixed pre-excitation. This appears to have happened due to infra-Hisian complete atrioventricular dissociation, which resulted from iatrogenic mechanical bumping of the left anterior fascicle in the background of right bundle branch block and left posterior hemiblock.

Efficient and chemoselective hydrogenation of aldehydes catalyzed by well-defined PN3-pincer manganese(II) catalyst precursors: an application in furfural conversion.

Well-defined and air-stable PN3-pincer manganese(II) complexes were synthesized and used for the hydrogenation of aldehydes into alcohols under mild conditions using MeOH as a solvent. This protocol is applicable for a wide range of aldehydes containing various functional groups. Importantly, α,ß-unsaturated aldehydes, including ynals, are hydrogenated with the CC double bond/CC triple bond intact. Our methodology was demonstrated for the conversion of biomass derived feedstocks such as furfural and 5-formylfurfural to furfuryl alcohol and 5-(hydroxymethyl)furfuryl alcohol respectively.

Aromaticity in catalysis: metal ligand cooperation via ligand dearomatization and rearomatization.

Unlike the conventional model of transition metal catalysis, ligands in metal-ligand cooperative (or bifunctional) catalysis are involved in the substrate activations. Such processes have offered unique mechanistic understandings and led to new concepts for the catalyst design. In particular, unprecedented activities were discovered when the ligand could undergo dearomatization-rearomatization reactions during the catalytic cycle. Aromatization can provide an extra driving force to thermodynamics; consequently, it brings a new perspective to ligand platform design for catalysis. While numerous applications were demonstrated, the influences of changing ligand aromatic properties were often overlooked. In this article, representative ligand systems will be highlighted and a comparison between the Milstein and the Huang pincer systems will be discussed to provide theoretical and conceptual insights.

Electrocatalytic Water Oxidation by a Phosphorus-Nitrogen O═PN3-Pincer Cobalt Complex.

Water oxidation is a primary step in natural as well as artificial photosynthesis to convert renewable solar energy into chemical energy/fuels. Electrocatalytic water oxidation to evolve O2, utilizing suitable low-cost catalysts and renewable electricity, is of fundamental importance considering contemporary energy and environmental issues, yet it is kinetically challenging owing to the complex multiproton/electron transfer processes. Herein, we report the first cobalt-based pincer catalyst for catalytic water oxidation at neutral pH with high efficiency under electrochemical conditions. Most importantly, ligand (pseudo)aromaticity is identified to play an important role during electrocatalysis. A significant potential jump (∼300 mV) was achieved toward a lower positive value when the aromatized cobalt complex was transformed into a (pseudo)dearomatized cobalt species. The dearomatized species catalyzes the water oxidation reaction to evolve oxygen at a much lower overpotential (∼340 mV) on the basis of the onset potential (at a current density of 0.5 mA/cm2) of catalysis at pH 10.5, outperforming other Co-based molecular catalysts reported to date. These observations may provide a new strategy for the judicious design of earth-abundant transition-metal-based water oxidation catalysts.

Acoustic Correlates of the Four-Way Laryngeal Contrast in Marathi.

The study examines acoustic correlates of the four-way laryngeal contrast in Marathi, focusing on temporal parameters, voice quality, and onset f0. Acoustic correlates of the laryngeal contrast were investigated in the speech of 33 native speakers of Marathi, recorded in Mumbai, India, producing a word list containing six sets of words minimally contrastive in terms of laryngeal specification of word-initial velar stops. Measurements were made for the duration of prevoicing, release, and voicing during release. Fundamental frequency was measured at the onset of voicing following the stop and at 10 additional time points. As measures of voice quality, amplitude differences between the first and second harmonic (H1-H2) and between the first harmonic and the third formant (H1-A3) were calculated. The results demonstrated that laryngeal categories in Marathi are differentiated based on temporal measures, voice quality, and onset f0, although differences in each dimension were unequal in magnitude across different pairs of stop categories. We conclude that a single acoustic correlate, such as voice onset time, is insufficient to differentiate among all the laryngeal categories in languages such as Marathi, characterized by complex four-way laryngeal contrasts. Instead, a joint contribution of several acoustic correlates creates a robust multidimensional contrast.

Double Dehydrogenation of Primary Amines to Nitriles by a Ruthenium Complex Featuring Pyrazole Functionality.

A ruthenium(II) complex bearing a naphthyridine-functionalized pyrazole ligand catalyzes oxidant-free and acceptorless selective double dehydrogenation of primary amines to nitriles at moderate temperature. The role of the proton-responsive entity on the ligand scaffold is demonstrated by control experiments, including the use of a N-methylated pyrazole analogue. DFT calculations reveal intricate hydride and proton transfers to achieve the overall elimination of 2 equiv of H2.

Hemilability-Driven Water Activation: A NiII Catalyst for Base-Free Hydration of Nitriles to Amides.

The NiII complex 1 containing pyridyl- and hydroxy-functionalized N-heterocyclic carbenes (NHCs) is synthesized and its catalytic utility for the selective nitrile hydration to the corresponding amide under base-free conditions is evaluated. The title compound exploits a hemilabile pyridyl unit to interact with a catalytically relevant water molecule through hydrogen-bonding and promotes a nucleophilic water attack to the nitrile. A wide variety of nitriles is hydrated to the corresponding amides including the pharmaceutical drugs rufinamide, Rifater, and piracetam. Synthetically challenging α-hydroxyamides are accessed from cyanohydrins under neutral conditions. Related catalysts that lack the pyridyl unit (i.e., compounds 2 and 4) are not active whereas those containing both the pyridyl and the hydroxy or only the pyridyl pendant (i.e., compounds 1 and 3) show substantial activity. The linkage isomer 1' where the hydroxy group is bound to the metal instead of the pyridyl group was isolated under different crystallization conditions insinuating a ligand hemilabile behavior. Additional pKa measurements reveal an accessible pyridyl unit under the catalytic conditions. Kinetic studies support a ligand-promoted nucleophilic water addition to a metal-bound nitrile group. This work reports a Ni-based catalyst that exhibits functional hemilability for hydration chemistry.

Inter-ligand electronic coupling mediated through a dimetal bridge: dependence on metal ions and ancillary ligands.

A series of Mo2, Ru2, Rh2 and Cu2 complexes with redox-active NP-R [2-(2-R)-1,8-naphthyridine; R = pyrazinyl (NP-pz, L1) and thiazolyl (NP-tz, L2)] ligands have been synthesized and characterized by X-ray crystallography and spectroscopic methods. Two NP-R ligands wrap the dimetal core by occupying four equatorial positions and two axial sites. The remaining four equatorial sites are engaged by bridging acetates in quadruply bonded cis-[Mo2(L1)2(OAc)2][BF4]2 (1), cis-[Mo2(L2)2(OAc)2][BF4]2 (1A), doubly bonded cis-[Ru2(L1)2(OAc)2][ClO4]2 (3), cis-[Ru2(L2)2(OAc)2][ClO4]2 (3A) and singly bonded trans-[Rh2(L1)2(OAc)2][BF4]2 (5) and trans-[Rh2(L2)2(OAc)2][BF4]2 (5A). Compounds cis-[Mo2(L1)2(CH3CN)4][BF4]4 (2), cis-[Mo2(L2)2(CH3CN)4][BF4]4 (2A), cis-[Ru2(L1)2(CO)4][OTf]2 (4) and cis-[Ru2(L2)2(CO)4][ClO4]2 (4A) contain acetonitriles or carbonyls as the ancillary ligands. The dicopper complexes trans-[Cu2(CH3CN)(L1)2][ClO4]2 (6) and trans-[Cu2(L2)2(ClO4)2] (6A) involve no bonding interaction between two Cu(i) units. Cyclic voltammogram studies reveal that two one-electron processes corresponding to each of the two ligands bound to the metal-metal bonded dimetal core result in four reversible one-electron reductions, with the exception of dirhodium(ii,ii) compounds 5 and 5A which show two one-electron reductions. The highest comproportionation constant (Kc) values are obtained for inter-valence complexes originating from the diruthenium(ii,ii) compounds 3 and 3A, whereas no electron delocalization is observed for dicopper(i,i) complexes 6 and 6A. The dimetal bridge and the ancillary ligands tune the degree of inter-ligand electronic coupling in these complexes. DFT calculations reveal a π*(NP)-δ*(M2)-π*(NP) orbital conduit for electron delocalization. For diruthenium(ii,ii) compounds 3 and 3A, an additional π*(NP)-π*(M2)-π*(NP) pathway is accessible contributing to high Kc values. The ancillary π-ligands (acetates and carbonyls) reduce the extent of the electron flow through π*(NP)-δ*(M2)-π*(NP) and thus lower the Kc values. The absence of metal-metal bond orbitals and the reduced metal-ligand covalency in dicopper(i,i) compounds are responsible for the lack of electron delocalization in these systems.

Clinicopathological Study of Uterine Leiomyomas: A Multicentric Study in Rural Population.

BACKGROUND AND OBJECTIVES: Leiomyoma of uterus forms the most common type of benign tumor of uterus and also the most common pelvic tumor in women. The symptomatology continues to be variable. Surgery has for long been the main mode of therapy for the myomas. For women who wish to retain the uterus for future pregnancies or other reasons, myomectomy is preferred. Recent trend has been toward nonsurgical approaches like GnRH hormone analogs/agonists, RU 486, or selective uterine artery embolization, laparoscopic cryoablation, radiofrequency thermal ablation, and MRGUs. This multicentric study was an attempt to analyze the clinicopathological spectrum in cases of leiomyoma of the uterus at Cheluvamba Hospital, Adichunchanagiri Institute of Medical Sciences, and to know regarding the pattern of presentation, pathological correlation, with type of fibroid, and endometrial and ovarian changes. METHODS: A clinical study of 100 cases of fibroid uterus was conducted in the Cheluvamba Hospital, attached to Mysore Medical College and Research Institute, Mysore, and Adichunchanagiri Institute of medical sciences, BG Nagara, Mandya from November 2008 to August 2012. The cases are selected by random allocation. On admission, detailed history, clinical examination, and investigations were recorded. RESULTS: Leiomyoma is the most common benign tumor of the uterus and commonly affects the women of child-bearing age, most commonly in the third decade, 55 %. The most common mode of presentation was menstrual disturbances (76 %), among which menorrhagia was seen in 54 % of the cases. Primary infertility was seen in 15 % of the patients. Intramural fibroids were the most common variety occurring in 60 % of the cases. Endometrial pattern was proliferative in 66.3 %. Cystic ovaries were seen in 8 % of the patients, adenomyosis in 16 % indicating hyperestrogenism. CONCLUSION: Fibromyoma (leiomyoma) is the most common benign tumor of the pelvis. It commonly affects the women of child-bearing age, mostly in the third decade and is most commonly seen in multipara. The most common mode of presentation is menstrual disturbances. Intramural fibroid is the most common variety. The proliferative and hyperplastic endometrium was commonly reported. The presence of proliferative endometrium, adenomyosis, and cystic ovaries all are indicative of hyperestrogenic state associated with development of fibroids.

Olefin oxygenation by water on an iridium center.

Oxygenation of 1,5-cyclooctadiene (COD) is achieved on an iridium center using water as a reagent. A hydrogen-bonding interaction with an unbound nitrogen atom of the naphthyridine-based ligand architecture promotes nucleophilic attack of water to the metal-bound COD. Irida-oxetane and oxo-irida-allyl compounds are isolated, products which are normally accessed from reactions with H2O2 or O2. DFT studies support a ligand-assisted water activation mechanism.

Abdominal hysterectomy: a new approach for conventional procedure.

OBJECTIVE: The present comparative study helps in developing a new approach to conventional hysterectomy procedure so as prevent intra-operative and Post-operative complications during the procedure. METHODS: Ligation of uterine and ovarian arteries was performed, prior to abdominal hysterectomy procedures, in Group A (n-1000) and conventional method of abdominal hysterectomy in Group B (n-450) from January 2000 to December 2009. It was a prospective study. RESULTS: In Group A it was noted that traumatic injury to (L) uterine vessel was present in 4 (0.4%) cases and (R) uterine vessel in 3 (0.3%) cases without any noticeable injury to the ovarian vessels, ureters or bladder as compared to in Group B where injury to (L) uterine was noted in 11 (2.4%) cases, ureters in 1 (0.1%) case, bladder in 6(1.5%) cases, hematoma in 10 (2.2%). Post-operative complications were found to be uneventful in Group A. CONCLUSION: The Present study concludes that ligation of uterine and ovarian arteries, prior to conventional abdominal hysterectomy procedures is found to be extremely safe procedure thereby reducing the risk of intra-operative and post- operative complications.

Origin of ovarian cancer: molecular profiling.

This is a review on the transition from our empirical approach to treat ovarian cancer to a specific treatment based on molecular signature. We have reviewed not only the evidence-based medicine focused on the origin and tumor morphology of ovarian cancer but also the molecular signature era based on molecular phenotyping of the tumor and its microenvironment, which influences the direct targeted therapy. Evidence-based medicine has shown that the targeted therapy studies are mainly biomarker driven, more focused, and hence treat only those patients who have the underlying molecular abnormality. This molecular abnormality is the target of the drug, leading to higher rates of response. These findings will carry important implications for screening, detection, and treatment of ovarian cancer in the future.

Maternal and perinatal outcome in teenage vs. Vicenarian primigravidae - a clinical study.

OBJECTIVES: The aim of this study was to evaluate the maternal and foetal outcomes and complications in teenage primigravida as compared to those in primigravidae who were aged 20-29 years. METHODS: Eighty teenage and one hundred sixty adult primigravidae were taken up for the study. Study duration was 24 months, from November 2010 to October 2012, at Rural Medical Research Centre in southern India. During this period, all cases were included in the study, irrespective of their booking statuses. For every teenage primigravidae, two subsequent adult primigravidae were correspondingly studied. Patients with major skeletal deformities such as kyphoscoliosis, polio, pelvic fractures, diabetes mellitus, renal disorders, morbid obesity were excluded. All cases of molar pregnancies and primigravidas who were admitted for abortions were also excluded. RESULTS: 38.75% of teenage primigravidae were unbooked as compared to 6.9% of adults. 68.75% of teenage primigravidae were anaemic as compared to 33.75% of adults. Antenatal complications like anaemia, hypertensive disorders of pregnancy, oligohydroamnios, hypothyroid were significantly more in teenagers (68.8%) as compared to those which were seen in adults(18.1%). 25% of teenagers had preterm births as compared to 5% adults who has preterm births. 43.75% of teenagers had Lower Segment Caesarean Section (LSCS) as compared to 20% adults who had LSCS. Indication was foetal distress in a majority of teenagers (68.5%). 29.2% of teenagers had low birth weight children as compared to 16.6% adults who had such children. 31.7% of teenage neonates required NICU admissions as compared to 12.27% neonates of adult mothers. INTERPRETATION AND CONCLUSION: It can be interpreted that teenage primigravidae had a significant number of complications in pregnancy, leading cause being anaemia, more preterm incidences and higher rates of LSCS, followed by higher number of NICU admissions. Since teenage pregnancy is a multifaceted problem, it demands multidimensional solutions. Teenage pregnancies are more common in populations with low socio-economic statuses, due to lack of education, awareness of complications of teenage pregnancies, and various other factors. Hence, awareness should be created and various programmes should be taken up, to educate mainly the poor in our rural setup. As early marriages cannot be prevented in our culture, so, possibly creating awareness on late conceptions is of utmost importance.

Desogestrel mini pill: is this safe in lactating mother?

To find out the safety, effectiveness and tolerability of using desogestrel (75 microg/day), a progesterone only pill on lactating mother, a prospective clinical study was undertaken among 200 lactating women during the period from 1st January 2010 to 13th June 2011 at Gice Clinic, Kalyani, Nadia, West Bengal. The same number of cases were taken as placebo for comparison. Desogestrel was started after six weeks of delivery for six months. Patients were reviewed at 8th, 12th, 16th, 24th weeks and one year. The very interesting results were found from the follow-up study that desogestrel (75 microg/day) did not alter the amount and composition of breast milk, pregnancy was not reported as compared to placebo. The drug had good tolerability, less side-effects and did not affect the growth and development of breastfed babies. Due to the safety, good efficacy, tolerability and less side-effects it is concluded that desogestrel (75 microg/day) was well accepted in majority of women (97.5%) and provided good contraceptive efficacy during the lactating period. This treatment does not have any effect on the growth and development of breastfed baby.

Rare association of central pontine myelinolysis with infantile tremor syndrome.

Central pontine myelinolysis (CPM) is an acute demyelination within the central basis pontis. Though exact mechanism is not known it is seen commonly with rapid correction of hyponatremia and also with pontine ischemia or infarction, demyelinating diseases, pontine neoplasm and different metabolic diseases. We report a rare association of CPM in a patient of Infantile Tremor Syndrom (ITS). ITS is a syndrome of tremor, mental and physical retardation, pigmentary changes of hair and skin and anemia in malnourished children. Though first reported in Indian subcontinent many identical cases were reported from around the world. Our case is a 15 month old child with generalized tremor, mild hepatosplenomegaly with features of grade II malnutrition including skin and hair changes. All the signs and symtoms of tremor improved after treatment with the World Health Organization (WHO) protocol for protein energy malnutrition (PEM) and administration of propranolol without any side effects.