Thermomechanical Mechanisms of Reducing Ice Adhesion on Superhydrophobic Surfaces.

Superhydrophobic (SH) coatings have been shown to reduce freezing and ice nucleation rates, by means of low surface energy chemistry tailored with nano/micro roughness. Durability enhancement of SH surfaces is a crucial issue. Consequently, the present research on reducing ice adhesion is based on radiation-induced radical reaction for covalently bonding SiO2 nanoparticles to polymer coatings to obtain durable roughness. Results indicated that the proposed approach resulted in SH surfaces having high contact angles (>155°) and low sliding angles (<5°) with improved durability and transparency. In a subsequent stage, the synthesized SH coating was investigated for its icephobic characteristics using a variety of substrates. Results indicated that supercooled water drops bounced back when impinging on SH polycarbonate substrate and froze on SH copper substrate held at -10 to -30 °C and were easily peeled off when coated by ice formed during exposure to air/supercooled water drops at -20 °C. The ice shear adhesion investigation (at -20 °C) demonstrated reduction of shear adhesion to a variety of SH treated substrates having low thermal expansion coefficient (copper and aluminum) and high thermal expansion coefficient (polycarbonate and poly(methyl methacrylate)). It was concluded that the thermal mismatch between the adhering ice and the various substrates and its resultant interfacial thermal stresses affect the adhesion strength of the ice to the respective substrate.

Using networks to combine "big data" and traditional surveillance to improve influenza predictions.

Seasonal influenza infects approximately 5-20% of the U.S. population every year, resulting in over 200,000 hospitalizations. The ability to more accurately assess infection levels and predict which regions have higher infection risk in future time periods can instruct targeted prevention and treatment efforts, especially during epidemics. Google Flu Trends (GFT) has generated significant hope that "big data" can be an effective tool for estimating disease burden and spread. The estimates generated by GFT come in real-time--two weeks earlier than traditional surveillance data collected by the U.S. Centers for Disease Control and Prevention (CDC). However, GFT had some infamous errors and is significantly less accurate at tracking laboratory-confirmed cases than syndromic influenza-like illness (ILI) cases. We construct an empirical network using CDC data and combine this with GFT to substantially improve its performance. This improved model predicts infections one week into the future as well as GFT predicts the present and does particularly well in regions that are most likely to facilitate influenza spread and during epidemics.

Contralateral lateral rectus muscle recession in patients with Duane retraction syndrome type 3.

AIMS: The aim of this study was to evaluate the motor, sensory, functional, and head posture results of recession of the lateral rectus muscle contralateral to the involved eye in patients with exotropic Duane retraction syndrome (DRS) type 3. METHODS: This was a retrospective, longitudinal, observational study of a consecutive clinical case series. Of the 11 patients with DRS type 3 operated on at a tertiary medical center from 1977 to 2012, 8 underwent recession of the lateral rectus muscle contralateral to the involved eye (with combined Y-splitting of ipsilateral lateral rectus muscle in 3 of them). Full ophthalmic, orthoptic, and neurological examination was performed before and after surgery. Main outcome measures included intragroup changes in motor misalignment, abnormal head turn, ocular upshoot, and stereopsis. RESULTS: Mean patient age was 8.75±3.1 years at surgery. Mean exodeviation for distance was -17.3±3.5 prism diopters (PD) preoperatively and -4.0±6.1 PD postoperatively; corresponding values for near were -23.1±7.2 PD and -5.9±8.7 PD. Motor deviation improved by 77% for distance (P=0.017) and 74.5% for near (P=0.01). In 7/8 patients, the postoperative residual exodeviation (distance and near) was <8.0 PD. There was an 80% improvement in head turn, from 15.3±4° before surgery to 3.1±5.0° after (P=0.01). Stereopsis improved significantly in 6/8 patients. Findings remained stable during follow-up (mean duration 35.9±50.8 months, range 5-132 months). CONCLUSIONS: Contralateral lateral rectus muscle recession appears to be a promising technique for the treatment of moderate unilateral DRS type 3, with patients showing significant motor and functional improvement and a decrease in head turn.

Gender-dependent differences in biological rhythms of mice.

The advantage of a variable's rhythm resides in its optimal time-phasing. This implies that, for a given function, members of a species will strive to exhibit identical time-phasing namely, their inter-individual genetic differences will be masked. To examine the generality of this assumption we explored if inbred mice exhibit gender dependent differences in rhythm parameters of biochemical variables. Male and female mice, entrained by exposure to 12:12 light:dark illumination were sacrificed, every 3 hours over a 27 hours period. Activities of creatine-phosphokinase (CK) and alkaline- phosphatase (AP), white blood cell (WBC) counts and urea nitrogen (UN) concentration were determined at each time point. For each significant rhythm four parameters were computed: period, acrophase, mesor and amplitude. In addition two derived parameters were also calculated: relative-amplitude (RA) and the rate of change in RA (CRA) which provide information about the slope and width of the peak. Patterns of most variables exhibited a compound rhythm containing two significant periodicities. Gender dependent differences were documented in the parameters of most rhythms indicating that the genetic and physiological differences limit to a certain extent the phasing ability of the entraining signals and point to an independent control of each of the rhythm parameters.

Modification in the inherent mode of allelic replication in lymphocytes of patients suffering from renal cell carcinoma: a novel genetic alteration associated with malignancy.

Using fluorescence in situ hybridization (FISH) to interphase nuclei, we examined the replication timing of 1 allele relative to its counterpart in PHA-stimulated peripheral blood lymphocytes of normal subjects and patients suffering from a solid tumor (renal cell carcinoma). In the FISH assay, an unreplicated DNA sequence is identified by a single dot-like hybridization signal, whereas a replicated region gives rise to a duplicated, bipartite signal. Accordingly, lymphocytes of normal individuals show 2 patterns of allelic replication: (i) synchronized replication of allelic counterparts, as exemplified by the biallelically expressed loci TP53 and D21S55; and (ii) non-synchronized replication of allelic partners, as exemplified by the early and late replicating alleles of GABRB3, an imprinted locus subjected to monoallelic expression. However, when present in lymphocytes of the cancer patients, all 3 loci change their replication mode: alleles of TP53 and D21S55 become asynchronous, whereas the early replicating allele of GABRB3 delays replication, leading to relaxation in the imprinted mode of replication. Based on the tight relationship between temporal order of allelic replication and allelic mode of expression, the modified order of allelic replication observed in nonmalignant cells of individuals diagnosed with cancer represents a novel genetic alteration associated with malignancy. This alteration detected by simple cytogenetic means, applied to peripheral blood lymphocytes, offers a potential test for cancer identification. Genes Chromosomes Cancer 27:270-277, 2000.

Asynchronous replication of homologous alpha-satellite DNA loci in man is associated with nondisjunction.

We tested the hypothesis that loss of replication control of DNA loci associated with human centromeres affects the main centromere function, namely, ensuring proper sister chromatid separation and accurate chromosomal segregation during cell division. Applying one-color fluorescence in situ hybridization (FISH) to interphase nuclei, we studied the replication patterns of homologous DNA loci associated with human centromeres (alpha-satellite sequences) of chromosome pairs 10, 11, 17, and X in PHA-stimulated lymphocytes of female cancer patients with a familial predisposition to malignancy and normal, healthy women. Concomitantly, we measured the rates of aneuploidy for these chromosomes in the same cells. To elucidate the replication patterns of the various centromeric loci, we analyzed the replication-dependent configuration signals obtained following FISH with four chromosome-specific alpha-satellite probes. Our data showed an association between replication timing of alpha-satellite sequences and centromeric function. Chromosome pairs whose homologous alpha-satellite loci replicated highly synchronously revealed low rates of aneuploidy, whereas chromosome pairs with a slightly asynchronous replication pattern (i.e., short intervals between early- and late-replicating loci) revealed intermediate rates of aneuploidy, and chromosome pairs exhibiting asynchrony with long-time intervals between early- and late-replicating loci showed the highest rate of aneuploidy.

Time dependency of hematopoietic growth factor coupled to chronotoxicity of carboplatin.

A growing body of data suggests that cancer therapy may be improved and toxicity reduced by administration of antineoplastic agents and cytokines at carefully selected times of the day. The time-dependent effects of each of the drugs have been documented, but not their mutual time dependencies. In the present studies we sought to determine the best time for granulocyte colony-stimulating factor (G-CSF) administration after carboplatin treatment. Carboplatin was injected in different groups of ICR mice at four different circadian stages for 5 consecutive days. Mice were synchronized with an alternation of 12 h of light (from 6:00 a.m. to 6:00 p.m.) and 12 h of darkness. After the last injection, peripheral WBCs of three mice from each group were counted every 4 h over a 24-h period. Bone marrow toxicity was estimated with the mean 24-h WBC count. The most severe leukopenia occurred in the group injected at 3:00 p.m. - 9 h after light onset. The second set of experiments evaluated the time-dependent effect of G-CSF when singly injected or given after carboplatin injections for 5 days only at 3:00 p.m. G-CSF was injected into various groups on days 8 and 9 at the same four different circadian stages. On the 10th day after the first injection, peripheral WBCs of three mice from each group were counted every 4 h over a 24-h period. Time-dependent effects were observed when G-CSF was injected as a single agent. When G-CSF was given at various times to the group with the most severe carboplatin-induced leukopenia, peripheral WBC count recovery was monitored at all injection times; it reached its highest level (exceeding even that of the control) when G-CSF was injected at 3:00 a.m. Dosing times of both chemotherapy and growth factor are relevant for optimization of carboplatin's hematologic tolerability.

Daily rhythms in male mice meiosis.

Various processes associated with mammalian reproduction exhibit circadian rhythms, yet no information is available concerning the presence of rhythmicity in meiosis-the crucial process of the production of sex cells. Following meiosis in cells derived from male mice exposed in vivo to daily light-dark cycles (LD), we were able to demonstrate the existence of a clear 24h rhythmic pattern in the overall meiotic process, as well as in the production of spermatids, the immediate products of male meiosis and the precursors of male sex cells. On the other hand, cells of free-running male mice exposed to constant external conditions (light-light, LL) revealed a 12h rhythmic pattern in the overall meiotic process, indicating the endogenous nature of this rhythm. The existence of a 24h rhythm component in a long-lasting (approximately 12 days) process like meiosis suggests a time-dependent gating mechanism that controls the dynamics of miocyte arrest and release. The 12h rhythms observed in LL may indicate the presence of either a 12h rhythm component or of two 24h endogenous components, phased 12h from each other, that are coupled in daily LD cycles and split up in the free-running condition (LL). The rhythmic pattern observed in the course of male meiosis might have significant implications for male reproduction.

The Environmental Health Profile (EHP) for the Acre Valley (Israel): xenobiotics in animals and physiological evidence of stress.

The scope of this study was to analyse the levels of various xenobiotics in animals, wild and domestic, of the Acre Valley in the north of Israel, the most polluted and dense urbanised part of the country. The focus was placed upon the bioaccumulation of heavy metals, such as Pb, Hg, Cu, Zn, Al, Fe, as well as other elements and PCBs. Analysis was also performed on levels of cholinesterase and acetylcholinesterase in birds and man influenced by insecticides in the same region. For this study we used X-ray scanning electron microscopic (S.E.M.) electron probe, atomic absorption spectrophotometry, gas chromatography for PCBs and biochemical methods specific for enzymes. We studied four species of littoral molluscs, four species of birds and five species of mammals including dogs and cats. The results showed very high levels of metals and PCBs and enzyme deviations in birds and man around the sprayed cotton fields, as compared to man from the close to towns. All the collected data will serve as an Environmental Health Profile for immediate and future consideration.

Long ultradian rhythms in red blood cells and ghost suspensions: possible involvement of cell membrane.

Oscillations in glyceraldehyde-3-phosphate dehydrogenase (GAPD) and glucose-6-phosphate dehydrogenase (G6PD) activities were recorded in suspensions of intact human red blood cells (RBCs) exposed to various light regimens. The periods of these oscillations, defined as "long ultradian," ranged between 13 and 18 h regardless of light regimen. The patterns of enzymatic activities were the same when assayed at each time point, in full hypotonic hemolysates, and membrane-free hemolysates. However, if hemolysates were prepared by sonication the activity pattern did not exhibit significant oscillations and the activity was higher than that recorded in hypotonic hemolysates. The observed rhythms may reflect a time-dependent attachment and detachment of enzyme molecules from cell membrane, suggesting that at the bound state the enzyme molecules are (temporarily) inactive. Oscillations with similar long ultradian periods were also observed in Ca++ concentration of suspended RBCs and in the binding of Ca++45 to human RBC ghosts. Treatment of the RBCs with A2C or Diamide before the preparation of the ghosts changed or distorted the rhythmic pattern of Ca++45 binding. These results point to the role of the membrane in processing the long ultradian oscillations. The relation between this type of oscillations to circadian rhythm is discussed.

Increased spindle resistance to antimicrotubule agents in cells prone to chromosomal nondisjunction.

The cytological behavior of the spindle apparatus was studied in cells prone to nondisjunction (ND), i.e., PHA-stimulated lymphocytes derived from children suffering from different types of neoplasia. These cells, which exhibited a high frequency of nonspecific aneuploidy, revealed an increased resistance of the spindle fibers to colchicine, podophyllotoxin, and cold, which was several times that of lymphocytes derived from healthy children. The results are in accord with previous findings showing a high resistance of spindle microtubules to the antimicrotubular agents colchicine, podophyllotoxin, vinblastine, and cold in PHA-stimulated lymphocytes derived from individuals prone to meiotic ND. It is therefore assumed that high resistance of the spindle apparatus to antimicrotubule agents characterizes cells at high risk for aneuploidy, and possibly, the overstabilized spindle fibers are responsible for failure of chromosomal disjunction.

Penetration of E. coli and F2 bacteriophage into fish tissues.

Throughout the world, fish thrive in rivers, lakes and seawater polluted with wastewater. Furthermore, in some countries, wastewater-enriched fishponds are used for fish cultivation. One of the major constraints in using wastewater for aquaculture is the possible contamination of the fish by enteric pathogens (bacteria and viruses), which may penetrate and accumulate in fish tissue, and constitute a potential public health hazard, especially in countries in which raw fish are consumed. In order to evaluate the infection of fish cultivated in wastewater, controlled experiments were performed to study the penetration of bacteria and bacteriophage inoculated into water tanks in which the fish were maintained. Twenty to thirty Tilapia hybrids (Sarotherodon aureus x S. niloticus), of 100 gr average weight and some 20 cm long were introduced into a 1 m3 plastic tank, containing about 500 l tap water at a temperature of 20 degrees C. High protein fish feed was added at a rate of about 1% of body weight per day. Four experiments were performed using an inoculum of an E. coli strain resistant to streptomycin and nalidixic acid. One hour after inoculation, bacterial concentration was 10(5)-10(6)/ml tank water. Four experiments were carried out with F2 male-specific bacteriophage 10(3)-10(5)/ml tank water. In each experiment two fish were sacrificed at zero time (prior to introduction of inocula), and 1, 5, 24, 48 and 72 or more hours after inoculation. Water samples were withdrawn at the same intervals. The level of microorganisms was tested in the following tissues: digestive tract, skin, spleen, liver and muscle. E. coli assays were performed using the membrane filtration technique; phages were assayed, using E. coli host cells in a plaque assay. The results of the experiments indicate that notwithstanding the high E. coli concentration in the tank water, its level in the edible tissue (muscle) was low, and in no instance higher than the acceptable standard of 400 cfu/gr (International Commission for Food Specification, 1974). The maximum concentration of F2 phage detected in muscle tissue was 350 pfu/gr. There is no standard for virus concentration in edible tissue.

Increased spindle resistance to antimicrotubule agents in women of high risk for meiotic nondisjunction.

Spindle sensitivity of phytohemagglutinin (PHA)-stimulated lymphocytes to three antimicrotubule drugs was compared in two groups of women who differ in their predisposition to meiotic aneuploidy: young women of low-risk age (ranging from 22 to 34 years) and middle-aged women of high-risk age (ranging from 40 to 52 years). Numerical sensitivity values for the antimicrotubule drugs, colchicine, podophyllotoxin, and vinblastine were obtained for each woman by recording the percentage of fully arrested metaphases out of the total metaphase cell population, i.e., cells exhibiting short, thick, and condensed chromosomes with sister chromatids clearly separated at their distal parts. Sensitivity increased linearly with increasing drug concentrations and was highly correlated with youth: its rate was significantly higher for women of the low-risk group. In addition, dividing lymphocytes of young mothers (26-33 years old) of Down syndrome children revealed significantly lower sensitivity to colchicine and podophyllotoxin than those of all young women of the low-risk group and similar sensitivity to that of the middle-aged women, i.e., the high-risk age group. The data are consistent with the theory that factors involved in meiotic nondisjunction may be concurrently operating in somatic cells. These factors presumably shift the equilibrium between tubulin and microtubules towards microtubules stabilization and thereby affect some of their functions.

Circadian rhythms of enzymes' activity in mice tissues during exposure to continuous illumination.

Activity rhythms of enzymes were determined in various tissues of C57BL/6J male mice. The determinations were carried out on mice which were kept in 14 hr light: 10 hr dark regimen, and on day 2, day 5 and day 21 during exposure to continuous illumination. Locomotor activity rhythms were followed in light: dark and up to the seventh day in constant light. All the activities exhibited a significant circadian rhythm in the light: dark regimen. During the exposure to continuous illumination, the locomotor activity exhibit a free running circadian rhythm with a consistent 24 hr and 40 min, major period component. At the same time recording the rhythms of enzyme activity; enzymes exhibited various formats of response which differed from those of the locomotor activity. The results suggest that rhythms of enzyme activity, as well as the desynchronization of the rhythms, are not enzyme specific.