Time-Dependent Hydrothermal Synthesis of TiO2 in the Presence of Zn2+: Effects on Photoconductivity

Incorporation of zinc into the frustule of the freshwater diatom Stephanodiscus hantzschii

Postural changes and the difference of attitudes influence the reaction time of a limb muscle. The present study is a modification and extension of previous studies on influense of the position changes in the hip joint on the electromyographic reaction time (EMG-RT) and on the H-reflex of the soleus muscle in normal human subjects. Primarily, the aim of this study was to explore the relevant neurophysiological mechanism which control reaction time. In experiment I (Exp. I), the EMG-RT from the 20 subjects (16 males and 4 females) who reacted the plantar flexion at peep sound (1000 Hz, 100 db, 100 msec duration) were recorded from the soleus muscle at three different positions of the hip joint (neutral, externally and internally rotated positions). In experiment II (Exp. II), H-reflexes were elicited in the soleus muscle at the static three hip joint positions. In this case, H-reflexes were recorded under two conditions; one where the subjects' hip joint position was changed passively by the experimentor (20 subjects) and the other where the subjects voluntarily changed their hip joint position (10 subjects). In this way, obtained H-reflexes were measured from peak to peak. Those amplitudes of H-reflex were examined as an indicator of activation of alpha-motoneurons pool. Major results may be summarized as following: 1. The EMG-RT of internally rotated position was longer than that of neutral position, and the EMG-RT of externally rotated position was shorter than that of neutral position (Exp. I). 2. In both conditions, the H-reflex amplitudes of internally rotated position were smaller than those of neutral position, and the H-reflex amplitudes of externally rotated position were larger than those of neutral position (Exp. II). 3. Especially, this tendency was remarkable when the subjects voluntarily changed their hip joint position (Exp. II). From these results, the relevant neurophysiological mechanisms which control reaction time were discussed, and the scheme for an explanation of the relationship between the changes of reaction time and the excitabilities of alpha-motoneurons pool was suggested.

ABSTRACTFleishman's (1966) model of complex motor skill learning is applied to viscera) self‐regulation. Five different underlying abilities are illustrated: strength, endurance, steadiness, control precision, and reaction time. In the experiment, 16 subjects were pre and post tested with instructions alone for degree of cardiac Strength and Endurance control (SE) (maximally increase or decrease heart rate and sustain it for a minute) and degree of cardiac Reaction Time control (RT) (produce a small, 3 sec burst of increased or decreased heart rate as quickly as possible to the onset of a trial). All subjects received heart rate biofeedback during training, but half practiced SE while the other practiced RT. It was predicted that cardiac learning would be specific to the skill practiced during biofeedback, with little transfer to the other task. The data indicated that SE training led to improved SE control (30%) accompanied by a slight decrement in RT control (‐5%). Conversely, RT training led to markedly improved RT control (120%)H accompanied by a small decrement in SE control(18%). The value of conceptualizing complex visceral skills as reflecting learned patterns of underlying neurophysiological abilities is illustrated.

Bentonite modified with zinc enhances aflatoxin B1 adsorption and increase survival of fibroblasts (3T3) and epithelial colorectal adenocarcinoma cells (Caco-2)

Characterization of multifunctional solution-processed Sn1-xZnxS nanostructured thin films for photosensitivity and photocatalytic applications

Reaction Time Deficits and Parkinson's Disease

Effect of tire rubber ash and zinc sulfate on yield and grain zinc and cadmium concentrations of different zinc-deficiency tolerance wheat cultivars under field conditions

Assessment of zinc (Zn) phytoavailability by the newly developed technique of diffusive gradients in thin films (DGT) has started gaining more importance because of some advantages over routine soil extractants. A greenhouse study was conducted to determine Zn phytotoxicity thresholds and the phytoavailability of Zn to sorghum sudan (Sorghum vulgare var. sudanese) grass by DGT, compared with calcium chloride (CaCl2) extraction. Treatments were five Zn levels and two soil pH (6.5 and 6). To obtain various amounts of Zn phytoavailability, soils having two different pH values were amended with zinc sulfate (ZnSO4) at rates of 0, 150, 300, 600, and 1200 mg Zn kg−1. Control soil (pH = 6.5) was treated with predetermined elemental sulfur to create different soil pH values (6). Shoot and root Zn concentrations ranged from 27 to 827 mg kg−1 and 101 to 2858 mg kg−1, respectively. In general, the Zn concentrations in shoots and roots were increased by increasing Zn concentrations and soil pH. Increasing applied Zn to soil decreased the plant biomass yield and increased adsorption of Zn by DGT. Calcium (Ca) to Zn ratios for all treatments except controls were <26 for shoots and <13 for roots. The CaCl2‐extractable Zn and effective concentration (CE) correlated well with plant Zn concentration. A critical shoot Zn concentration for 90% of the control yield was chosen as an indicator of Zn toxicity. The performance of DGT, CaCl2 extraction, Ca/Zn ratio and plant Zn concentrations were similar for assessing Zn phytoavailability.

An experiment was conducted to compare the effects of zinc sulfate (ZS) and tribasic zinc sulfate (TBZ) as sources of supplemental zinc on growth performance, serum zinc (Zn) content and messenger RNA (mRNA) expression of Zn transporters (ZnT1/ZnT2/ZnT5/ZIP4/DMT1) of young growing pigs. A total of 96 Duroc×Landrace×Yorkshire pigs were randomly allotted to two treatments and were fed a basal diet supplemented with 100mg/kg Zn from either ZS or TBZ for 28days. Feed:gain ratio in pigs fed TBZ were lower (P<0.05) than pigs fed ZS, and average daily weight gain tended to increase (0.05≤P≤0.10) in pigs fed TBZ. Compared with pigs fed ZS, pigs fed TBZ had a higher CuZn-superoxide dismutase and Zn content in serum (P<0.05) while they had a lower Zn content in feces (P<0.05). In addition, ZIP4 mRNA expression of zinc transporter in either duodenum or jejunum of pigs fed TBZ were higher (P<0.05) than pigs fed ZS. These results indicate that TBZ is more effective in serum Zn accumulation and intestinal Zn absorption, and might be a potential substitute for ZS in young growing pigs.

A 126-d study utilized 72 Angus-cross steers (411 ± 16 kg) in a 3 × 2 factorial to examine the effects of Zn source and implant strategy on performance, carcass characteristics, and tissue Zn concentrations. All steers received 70 mg Zn/kg dry matter (DM) from ZnSO4 + 30 mg Zn/kg DM from one of three sources: zinc hydroxychloride (ZnHC), zinc glycinate (ZnG), or zinc sulfate (ZnS). Implant (IMP) strategies included: no implant (NoIMP) or Component TE-IS and Component TE-200 (IS/200) on d 0 and 57, respectively. Steers were blocked by weight into pens of 6 and fed a dry rolled corn-based diet via GrowSafe bunks. Data were analyzed using ProcMixed of SAS, with fixed effects of Zn, IMP, and the interaction. Liver and muscle collected on d -5, 14, 71, and 120 were analyzed for Zn concentration and data were analyzed as repeated measures (repeated effect = day). Steer was the experimental unit (n = 12/treatment). Final body weight and overall average daily gain tended to be decreased for ZnHC compared to ZnS, with ZnG intermediate within IS/200 (Zn × IMP; P ≤ 0.07). No interaction was observed for overall G:F or DM intake (P ≥ 0.41), but both were greater for implanted steers (P ≤ 0.01), while overall G:F was improved for ZnS compared to ZnHC and ZnG (P = 0.02). Carcass characteristics were unaffected by Zn × IMP or Zn source (P ≥ 0.12), but IS/200 improved HCW, DP, and REA (P ≤ 0.01). Implant increased liver Zn (P = 0.02) concentrations. Within IS/200 ZnG tended to have greater muscle Zn than ZnS while ZnHC was intermediate (Zn × IMP; P = 0.09), potentially indicating differences in availability of Zn source to growing muscle. These data suggest Zn source and implant influence performance and tissue Zn concentrations.

Catalytic properties of silica supported titanium, vanadium and niobium oxide nanoparticles towards the oxidation of saturated and unsaturated hydrocarbons

Texting while driving is a visual problem influenced by phone viewing angle and working distance in young individuals

Understanding and directing the energy transfer in nanocrystals-chromophore heterostructure is critical to improve the efficiency of their photocatalytic and optoelectronic applications. In this work, we studied the energy transfer process between inorganic-organic molecular complexes composed of cesium halide perovskite nanoplatelets (CsPbBr3 NPLs) and boron dipyrromethene (BODIPY) by photoluminescence spectroscopy (PL), time-correlated single photon-counting (TCSPC) and femtosecond transient absorption spectroscopy. The quenching of PL in CsPbBr3 NPLs occurred simultaneously with the PL enhancement of BODIPY implied the singlet energy transfer process. The rate of energy transfer has been determined by transient absorption spectrum as kET = 3.8 × 109 s-1. The efficiency of Förster energy transfer (FRET) has been quantitatively calculated up to 70%. Our work advances the understanding of the interaction between BODIPY and perovskite nanoplatelets, providing a new solution based on their optoelectronic and photocatalytic applications.

The effects of fortification of two different flours with 60 ppm Fe, 60 ppm Fe plus 2 ppm folic acid, 60 ppm Fe plus 30 ppm Zn and 30 ppm Zn were investigated. Iron and Zn were applied from the source of ferrous sulfate and zinc sulfate, respectively. Fortification treatments had significant effects on Zn and Fe concentrations in the flour, dough and bread. Addition of Zn to the flour significantly (P < 0.05) decreased the molar ratio of phytic acid to Zn in bread. Fortification of flour with ferrous sulfate impaired the color, taste and overall acceptability of Khabbazi bread. Double fortification of flours with Fe and Zn is useful to enhance nutritional quality of food, but addition of Fe may adversely change the color, taste and overall acceptability of bread. PRACTICAL APPLICATIONS Regarding low Fe and Zn concentrations and consequently poor nutritional quality of wheat flours distributed across the country, co-fortification of flours seems necessary. The result of this study showed that double fortification of flours with Fe and Zn is useful to enhance nutritional quality of bread. This would improve Fe and Zn status of people. Sensory attributes are important parameters to be considered in order to success flour fortification program in the case of iron. Iron addition significantly affects sensory characteristics including color, taste and overall acceptability of the bread. Thus, addition of ferrous sulfate to flour may impair acceptability of the bread. Flour fortification with zinc sulfate would greatly enhance Zn concentration in both dough and bread. Among the treatments of this study, bread produced from Zn-fortified Khabbazi flours had the best sensory characteristics and nutritional quality.

The Effects of Dietary Zinc Concentration and Source on Yearling Bull Growth and Fertility