An efficient perovskite solar cell with symmetrical Zn(ii) phthalocyanine infiltrated buffering porous Al2O3 as the hybrid interfacial hole-transporting layer.

A new Zn(ii) phthalocyanine (Pc) based low bandgap HTM is introduced for perovskite solar cells. Steady state and time-resolved photoluminescence (PL) measurements indicated an evenly matched hole extraction efficiency between sym-HTPcH and spiro-OMeTAD. On account of the low film quality and resulting high recombination, Zn(ii) Pc normally cannot work as an effective HTM. We adopted insulating Al2O3 for the infiltration of sym-HTPcH to form a hybrid interfacial buffer layer, affording perovskite solar cells (PSCs) with an average PCE value of up to 12.3%, which is a significant improvement with respect to the control cell without the meso-Al2O3 layer (4.21%) and is the highest value ever reported for Zn(ii) phthalocyanine based devices under AM1.5G standard conditions. A hysteresis test revealed that our device structure with the new HTM exhibited a balanced charge extraction behaviour.

Synthesis and characterization of donor-π-acceptor-based porphyrin sensitizers: potential application of dye-sensitized solar cells.

New porphyrin sensitizers based on donor-π-acceptor (D-π-A) approach have been designed, synthesized, characterized by various spectroscopic techniques and their photovoltaic properties explored. N,N'-Diphenylamine acts as donor, the porphyrin is the π-spacer, and either carboxylic acid or cyanoacryclic acid acts as acceptor. All compounds were characterized by using (1)H NMR spectroscopy, ESI-MS, UV-visible emission spectroscopies as well as electrochemical methods. The presence of aromatic groups between porphyrin π-plane and acceptor group push the absorption of both Soret and Q-bands of porphyrin towards the red region. The electrochemical properties suggests that LUMO of these sensitizers above the TiO2 conduction band. Finally, the device was fabricated using liquid redox electrolyte (I(-)/I3(-)) and its efficiency was compared with that of a leading sensitizer.

Growth pattern of the Sugalis--a tribal population of Andhra Pradesh, India.

With a view to assess physical growth, a cross-sectional study was made on 1565 Sugali children (854 boys and 711 girls), aged 1 to 20 years. Anthropometric measurements included height, weight, upper arm circumference, biacromial diameter, biiliocristal diameter, chest circumference, head circumference and skinfold measurements at triceps, subscapular, suprailiac and medial calf. All anthropometric measurements except skinfold measurements exhibit uniform increase with age in both the sexes. A gradual increase in four skinfold measurements is observed with age in the case of girls, whereas slight decrease is observed in the case of the boys. The Sugali boys and girls are shorter and lighter than well-to-do Indian standards. The median heights and weights of Sugali boys and girls fall below the 5th percentile of NCHS standards. Finally, the results were discussed with a comparative view point.

alphaA- and alphaB-crystallins protect glucose-6-phosphate dehydrogenase against UVB irradiation-induced inactivation.

alpha-Crystallin, a major eye lens protein, has been shown to function like a molecular chaperone by suppressing the aggregation of other proteins induced by various stress conditions. Ultraviolet (UV) radiation is known to cause structural and functional alterations in the lens macromolecules. Earlier we observed that exposure of rat lens to in vitro UV radiation led to inactivation of many lens enzymes including glucose-6-phosphate dehydrogenase (G6PD). In the present paper, we show that alpha-crystallin (alphaA and alphaB) protects G6PD from UVB irradiation induced inactivation. While, at 25 degrees C, there was a time-dependent decrease in G6PD activity upon irradiation at 300 nm, at 40 degrees C there was a complete loss of activity within 30 min even without irradiation. The loss of activity of G6PD was prevented significantly, if alphaA- or alphaB-crystallin was present during irradiation. At 25 degrees C, alphaB-crystallin was slightly a better chaperone in protecting G6PD against UVB inactivation. Interestingly, at 40 degrees C, alphaA- and alphaB-crystallins not only prevent the loss of G6PD activity but also protect against UVB inactivation. However, alphaA- and alphaB-crystallins were equally efficient at 40 degrees C in protecting G6PD.

Reduced levels of rat lens antioxidant vitamins upon in vitro UVB irradiation.

Ultraviolet (UV) radiation is one of the major risk factors of cataractogenesis. UV radiation induced damage to the eye lens is believed to be mediated through reactive oxygen species. Antioxidant defense systems, enzymatic and non-enzymatic, resist this damage. In the present study, the levels of rat lens endogenous antioxidants, L-ascorbic acid, alpha-tocopherol and beta-carotene, have been determined by HPLC upon in vitro UVB irradiation. UVB irradiation for 24 h (300 nm; 100 µW/cm(2)) of three months old rat lens suspended in RPMI medium, leads to 69-89% decrease in endogenous levels of these antioxidants. The addition of ascorbic acid (2 mM), alpha-tocopherol (2.5 µM) or beta-carotene (10 µM), separately to the medium during irradiation significantly prevented the decrease in their endogenous levels, thereby suggesting a protective role for these antioxidant micronutrients against photodamage to the eye lens.

Airborne radon and its progeny levels in the coal mines of Godavarikhani, Andhra Pradesh, India.

In India, out of about 0.7 million miners, nearly 0.5 million persons are directly engaged in coal operations. Radon and its progeny levels have been quantified in the coal-mining environment of Godavarikhani, Andhra Pradesh, India using solid-state nuclear track detectors. Seasonal and mine depth variations in radon levels have been recorded resulting in the identification of locations with a high radon level as areas with no mining activity, active mining operational zones and return air ventilation paths. All these radon levels were below the permissible levels. The average concentrations of radon and its progeny levels were found to be 144 +/- 61 Bq m(-3) and 20 +/- 11 mWL (working level) respectively in the two-incline mine, and these values for the five-incline mine are recorded as 315 +/- 71 Bq m(-3) and 30 +/- 9 mWL respectively.