Use of cryopreserved spermatozoa for caprine in vitro fertilization (IVF).

Proceedings Annual Conference of the International Embryo Transfer Society, Nice Acropolis, Nice, France, Jan., 1997

Effects of EGTA and cytochalasin-B during freezing and vitrification of immature and mature bovine and rhesus monkey (M. mulatta) oocytes.

Cryopreservation procedures have been shown to be extremely disruptive to the plasma membrane and intracellular organization of mammalian oocyte. Cytochalasin-B (Cyt-B) or EGT A may stabilize oocyte cytoskeletal elements prior to Cryopreservation and make the plasma membrane less rigid and more elastic to avoid injury during the osmotic stresses of freezing. Experiments were conducted to assess the morphological viability and developmental potential of bovine and rhesus monkey oocytes roter exposure to Cyt-B or EGTA prior to freezing and vitrification. ln the bovine experiments: The methods of oocyte isolation, in vitro maturation (IVM), in vitro fertilization (IVF) , and embryonic development (IVC) were as described elsewhere (Biol Reprod. 55:333-339, 1996). AIl data were analyzed by ANOV A and Chi-square using "StatMost" for Windows. ln an initial experiment, a group of ilnmature (GV) oocytes and oocytes roter IVM (ova) were randomly selected and pretreated for 5 min with EGTA (O.IM) or Cyt-B (Img/ml) without cryoprotectant (CPA), and another group were equilibrated for 15 min with the CPA (1.5 M ethylene glycol mixed with 0.5 M glycerol in PHS) roter pretreatment with EGTA or Cyt-B. AIl oocytes were diluted and/or washed and immediately used for IVM and/or IVF and IVC. No significant differences in cleavage (C) development and blastocyst (B) hatching among treatments in the GV oocytes group. Percentages of early C, morula (M), B, and expanded B (EB) development ranged 72-82%, 53-65%, 40-47% and 25-35% respectively. Ova treated with EGTA without CPA produced significantly (P<.05) higher C (31/41,75%), M (48.8%), B (40%) and EB (24.4%) than with Cyt-B. ln the slow freezing experiment, a total of 105 GV oocytes and 155 ova were exposed to (a) zero (b EGTA, or ~) Cyt-B before equilibration with CPA + 0.5 sucrose in PHS plus 15% Fetal bovine serum (PBS/FBS). Gametes were loaded into sterile cryovials, cooled at 2°Chnin to -7°C, seeded, cooled at 0.3°Chnin to -32°C, then plunged in LN2. They were thawed.in air (10 sec), then wann water (35°C), and diluted out of CPA in 3 steps (1, 0.5, 0.2 M sucrose). Three replicated showed that although many of the frozen-thawed oocytes/ova survived as judged by morphology (range 70-80%), their developmental potential was severely retarded. C ranged between 0% to 14.3%. ln the vitrification experiment, a total of 135 GV oocytes and 90 ova were grouped as above and vitrified in straws containing a mixture of 3.25M glycerol and 4.5M ethylene glycol plus 0.5 sucrose in PBS/FBS. Here, higher (P<.05) morphological survival rates (98%) foIlowed pretreatment with EGT A. However, the developmental potential was very low among aIl groups ranging between 0% to 17.7%. ln the monkey experiments: The methods of oocyte isolation, IVM and IVF was as described ( Theriogenology 43:362, 1995). A total of 72 GV oocytes and 42 ova were subjected to slow rate freezing and vitrification in groups as described for cow oocytes above. Pretreatment of both GV oocytes or ova with EGTA or Cyt-B prior to freezing or vitrification resulted in 77.6% morphological survival which was significantly (P<.OI) higher than for the control (50%). No differen?s in fertilization and development were detected mnong treatment. Per?ntages of C to 4-?Il stage ranged from 50-67%. Results suggest prefreeze treatment with EGTA and/or Cyt-B may be useful in enhancement of oocyte/ovum cryopreservation.Proceedings Annual Conference of the International Embryo Transfer Society, Nice Acropolis, Nice, France, Jan., 1997

Impact of mobile phones and wireless devices use on children and adolescents´ mental health: a systematic review

Growing use of mobiles phones (MP) and other wireless devices (WD) has raised concerns about their possible effects on children and adolescents’ wellbeing. Understanding whether these technologies affect children and adolescents’ mental health in positive or detrimental ways has become more urgent following further increase in use since the COVID-19 outbreak. To review the empirical evidence on associations between use of MP/WD and mental health in children and adolescents. A systematic review of literature was carried out on Medline, Embase and PsycINFO for studies published prior to July 15th 2019, PROSPERO ID: CRD42019146750. 25 observational studies published between January 1st 2011 and 2019 were reviewed (ten were cohort studies, 15 were cross-sectional). Overall estimated participant mean age and proportion female were 14.6 years and 47%, respectively. Substantial between-study heterogeneity in design and measurement of MP/WD usage and mental health outcomes limited our ability to infer general conclusions. Observed effects differed depending on time and type of MP/WD usage. We found suggestive but limited evidence that greater use of MP/WD may be associated with poorer mental health in children and adolescents. Risk of bias was rated as ‘high’ for 16 studies, ‘moderate’ for five studies and ‘low’ for four studies. More high-quality longitudinal studies and mechanistic research are needed to clarify the role of sleep and of type of MP/WD use (e.g. social media) on mental health trajectories in children and adolescents

Preparation of controlled release microspheres using supercritical fluid technology for delivery of anti-inflammatory drugs

Ethylcellulose/methylcellulose blends were produced using different precipitation techniques and impregnated with naproxen, a non-steroidal anti-inflammatory drug (NSAID). Solvent-evaporation technique was used not only for the preparation of ethylcellulose/methylcellulose microspheres but also to encapsulate naproxen. Supercritical fluid (SCF) impregnation was also performed to prepare naproxen loaded microspheres. The microspheres, impregnated by the SCF technique, were prepared both by solvent-evaporation and by a supercritical antisolvent (SAS) process. In vitro release profiles at pH 7.4 and 1.2, of naproxen-loaded microspheres were evaluated and the results were modelled Fick’s law of diffusion and Power law. Miscrospheres prepared by supercritical antisolvent have a higher loading capacity and present a slower release profile. The systems studied present a release mechanism controlled by drug diffusion which complies Fick’s law of diffusion

Preparation of ethylcellulose/methylcellulose blends by supercritical antisolvent precipitation

The supercritical antisolvent (SAS) techniquewas used to prepare ethyl cellulose/methyl cellulose blends, two biocompatible polymers commonly used as drug carriers in controlled delivery systems. Ethyl cellulose is widely used as a drug carrier. The drug release of the delivery devices can be controlled to some extent by addition of a water-soluble or water swellable polymer, such as methyl cellulose. This leads to the solubility enhancement of poorly water-soluble molecules. SAS experiments were carried out at different operational conditions and microspheres with mean diameters ranging from 5 to 30 m were obtained. The effect of CO2 and liquid flow, temperature and pressure on particle size and particle size distribution was evaluated. The microspheres were precipitated from a mixture of dichloromethane (DCM) and dimethylsulfoxide (DMSO) (4:1 ratio). The best process conditions for this mixture were according to our study 40 ◦C and 80 bar

Blind signatures from Zero knowledge in the Kummer variety

We show how to apply the BZ methodology (Blind signatures from Zero knowledge) to obtain blind signatures in the Kummer varieties defined by Montgomery curves. We also describe specially-tailored arithmetic algorithms to facilitate their efficient implementation. The result can be proved secure under appropriate assumptions, appears to resist even the ROS attack (to which most elliptic-curve blind signature schemes succumb), and is arguably one of the most efficient among those proposals that offer similar security guarantees

Estimativas da interação genótipo x ambiente (GA) em progênies de sorgo forrageiro desenvolvidas pelo IPA - Instituto Agronômico de Pernambuco.

Resumo: Em face da instabilidade climática do semiárido brasileiro, notadamente quanto à escassez e a distribuição errática das chuvas, o sorgo forrageiro que apresenta características de xerofilia detém a vantagem sobre a maioria das plantas forrageiras recomendadas para a região como suporte a pecuária, no atendimento de volumosos no período estival do ano. Foi utilizada a metodologia AMMI - ?Additive Main Effects and Multiplicative Interaction? (Análise de Efeitos Aditivos Principais e Interação Multiplicativa) que investiga a interação genótipo ambiente, e tem sido usada por vários autores e em diversas culturas. O objetivo deste trabalho foi avaliar o comportamento de 30 genótipos de sorgo forrageiro testados em seis ambientes do semi-árido de Pernambuco e de Alagoas usando a técnica AMMI visando recomendação. Os genótipos foram desenvolvidos pelo IPA a partir do método sequencial de pedigree, oriundos de cruzamentos e de autofecundações sucessivas até gerações avançadas. Através da análise infere-se que os genótipos G14, G22, G27 e G5 podem ser considerados estáveis e os genótipos G16 e G7 foram os que mais contribuíram com a interação GA