Cervical tumoral calcinosis with secondary hyperparathyroidism in a chronic hemodialysis patient

Tumoral calcinosis is an uncommon and severe complication of chronic renal failure. It is generally associated with the presence of a high‐serum calcium‐and‐phosphorus product. We report here a case of a patient on maintenance hemodialysis who presented with progressively increasing, solitary, tumor‐like swelling over the nape of the neck. A 50‐year‐old female on thrice weekly maintenance hemodialysis for the last 3 years presented with a small swelling over the nape of the neck that had been progressively increasing over the last 1 year to cricket ball size. The patient was investigated and diagnosed as having tumoral calcinosis. The metastatic calcification occurring in the patient was most likely related to high calcium × phosphate product with coexistent secondary hyperparathyroidism possibly aggravated by vitamin D therapy. The patient was treated with withdrawal of vitamin D therapy, strict control of serum phosphate levels with noncalcemic phosphate binders, and subtotal parathyroidectomy. The neck swelling started decreasing in size after 2 months of parathyroidectomy and there was marked clinical improvement with drop in serum parathormone levels, over a period of 6 months. After 2 years of parathyroidectomy, the neck swelling again started increasing in size with increase in serum parathormone levels. The patient was treated with cinacalcet and the neck swelling gradually decreased in size along with control of serum parathormone and phosphate levels.     

Gene–gene and gene–environment interactions in complex traits in yeast

One of the fundamental questions in biology is how the genotype regulates the phenotype. An increasing number of studies indicate that, in most cases, the effect of a genetic locus on the phenotype is context‐dependent, i.e. it is influenced by the genetic background and the environment in which the phenotype is measured. Still, the majority of the studies, in both model organisms and humans, that map the genetic regulation of phenotypic variation in complex traits primarily identify additive loci with independent effects. This does not reflect an absence of the contribution of genetic interactions to phenotypic variation, but instead is a consequence of the technical limitations in mapping gene–gene interactions (GGI) and gene–environment interactions (GEI). Yeast, with its detailed molecular understanding, diverse population genomics and ease of genetic manipulation, is a unique and powerful resource to study the contributions of GGI and GEI in the regulation of phenotypic variation. Here we review studies in yeast that have identified GGI and GEI that regulate phenotypic variation, and discuss the contribution of these findings in explaining missing heritability of complex traits, and how observations from these GGI and GEI studies enhance our understanding of the mechanisms underlying genetic robustness and adaptability that shape the architecture of the genotype–phenotype map.     

Carbon nanostructures as catalyst for improving the hydrogen storage behavior of sodium aluminum hydride

The present paper reports the catalytic effect of carbon nanomaterials, particularly carbon nanotubes (CNTs) and graphitic nanofibres (GNFs) with two different structure morphology, namely planar GNFs (PGNFs) and helical GNFs (HGNFs) as the catalyst for improving the dehydrogenation and rehydrogenation behavior of sodium aluminum hydride (NaAlH₄). It has been observed that HGNFs posses superior catalytic activity than other carbon nanoforms in improving the desorption kinetics and decreasing the desorption temperature of NaAlH₄. Temperature programmed desorption (TPD) reveals that HGNFs admixed NaAlH₄ undergo hydrogen desorption at a much lower temperature than PGNFs and CNTs (SWCNTs and MWCNTs) admixed NaAlH₄. Thus for the heating rate of 2 °C/min, the peak desorption temperature corresponds to initial step decomposition of NaAlH₄ admixed with 2 wt.% HGNFs and 2 wt.% PGNFs has been lowered to 143.6 °C and 152.6 °C, respectively (for pristine NaAlH₄, it is ∼170 °C). In addition to the enhancement in desorption kinetics, the HGNFs admixed NaAlH₄ undergoes fast rehydrogenation at the moderate condition. Microstructural investigation reveals that the HGNFs were present on the surface of NaAlH₄ grains, whereas CNTs were tunneled into the grains of NaAlH₄ suggesting a distinct catalytic behavior of different carbon nanovariants.     

Progress in renewable energy under clean development mechanism in India

Kyoto protocol was the first agreement regarding control of climate change problems. Clean development mechanism (CDM) was included in the Kyoto protocol to promote sustainable development in developing countries (non-Annex I countries) and assist developed countries (Annex I countries) to achieve their emission reduction targets. CDM allows trading of emissions reductions and helps to increase sustainable development in a developing country and reduce global emissions in developed country. Renewable energy sources are the appropriate alternatives for sustainable development through CDM. India is one of the emerging nations in renewable energy sector. Government of India is trying to enhance energy generation through renewable and carbon trading. This paper shows the current status and progress of renewable energy through CDM in India.     

Properties of rice soils affecting methane production potentials: 2. Differences in topsoil and subsoil

Methane (CH₄) is one of the important greenhouse gases accounting for 15% of the total enhanced greenhouse effect. A laboratory experiment was conducted with nine soils from the Philippines and two soils from India to determine the CH₄ production potential of topsoil and subsoil, and to assess the role of different fractions of soil organic C in influencing CH₄ production potential. CH₄ production potentials of topsoils varied in a wide range from 20 g g^–1 soil (Urdaneta soil) to 837 g g^–1 soil (Pila soil) over 100 d of incubation. In contrast, CH₄ production potentials of subsoils were low (< 2 g g^–1 soil over 100 d of incubation). The topsoil was the main source of CH₄ in the flooded rice soils contributing 99.95% to the total CH₄ production while the subsoil contributed negligibly (0.05%). CH₄ production potentials of the topsoils showed significant correlation with cation exchange capacity (CEC), total N and available K contents of soils. For the subsoils, CH₄ production potentials had a significant correlation with available P and clay contents of the soils. Considering the differences in all the soil properties and the CH₄ production potentials between topsoils and subsoils, a significant relationship of CH₄ production potential with CEC, available K and enriched C (extra C content of topsoil compared to that of subsoil) was obtained. Two carbon fractions, water soluble C (H₂O-C) and carbon mineralised under anaerobic conditions (AnMC) affected total CH₄ production indirectly rather than directly.     

Properties of rice soils affecting methane production potentials: 1. Temporal patterns and diagnostic procedures

Thirty-one rice soils from different locations in the Philippines were incubated anaerobically for 100 d to determine methane (CH₄) production potentials and to establish relationships between physico-chemical properties of soil and CH₄ production potential. These soils showed pronounced variations in pattern and magnitude of CH₄ production. Total CH₄ production over 100 d incubation ranged from 163 to 837 g CH₄ g^–1 soil. Total N, soil texture (clay and sand fractions mainly) and cation exchange capacity (CEC) of the soils had significant effect on CH₄ production potential. Available K and active Fe content also affected the CH₄ production potentials of various soils. An assessment of CH₄ production with high accuracy could be obtained from soil redox potential (Eh) development during incubation; the difference between initial and equilibrium Eh allowed a computation of CH₄ production with more than 70% reliability. The CH₄ production potentials obtained over long incubation periods could be assessed, with reasonable accuracy, by a relatively short incubation experiments and fewer measurements of CH₄ production. Only three samplings of CH₄ production rate within a short incubation period of 37 d facilitated a prediction of total CH₄ production over 100 d incubation using the following algorithm:P _0-100=99.21+10.79X₄+11.69X₁₆+45.79X₃₇ (R²=0.91; P<0.01),where P _0-100 is the total CH₄ production during 100 d of incubation and X _n is CH₄ production rate at n days of incubation. Longer incubation periods (86 d) were required to achieve a reliability of more than 95%.     

Fracture of fibrous metal matrix composites—III. effect of imperfection geometry and heat treatment

The work of Dvorak et al. and Bahei-El-Din et al. (1989) on fracture of unidirectionally reinforced boron/aluminum specimens with a center notch is extended here for specimens with various imperfection geometries and heat treatment. The experimental results indicate that long, discrete plastic shear zones similar to those found at the notch tips are present in all specimens. The measured fracture strength was not affected by the notch shape, but was affected by the heat treatment. Finite element analysis of selected specimens indicated that the fracture criterion proposed in parts I and II is applicable to as-fabricated or annealed B/A1 specimens with any notch geometry. Namely, failure is controlled by a critical ratio of the largest principal stress to off-axis unnotched strength in the principal direction, in a small representative volume in the vicinity of the notch. This criterion, however, does not apply for specimens tested in the overaged (T6) condition.     

Experimental studies on electrical discharge wire cutting of Ni-rich NiTi shape memory alloy

The experimental investigation explores the effect of electrical discharge wire cutting (EDWC) variable parameters such as spark gap voltage, wire tension, pulse off time, wire feed rate, and pulse on time on the surface roughness, average cutting rate, and metallographic changes of Ni_55.95Ti_44.05 shape memory alloy (SMA). The spark gap voltage, pulse off time, and pulse on time have the significant effect on the surface roughness and average cutting rate, whereas wire tension and wire feed rate have the trifling effect. Ni_55.95Ti_44.05 SMA’s surface after EDWC is characterized by many discharge craters, microcracks, voids, and white layer of resolidified molten material. The elemental composition analysis of white layer using energy-dispersive spectroscopy divulges the deposition of the foreign element from the brass wire as well as the dielectric on the surface after EDWC. The machined surface as well as the wire electrode surface consists of various compounds of Ti, Ni, Zn, and Cu which have been identified by X-ray diffraction peak analysis.