Screening of conditions for rapid freezing of human oocytes: preliminary study toward their cryopreservation.

One hundred and twenty-one freshly-collected human oocytes and 839 unfertilized human oocytes after insemination were cryopreserved by vitrification. The cryoprotectants used were dimethylsulfoxide (DMSO) and sucrose. Vital staining and morphological criteria were used to assess injuries to cells. Variation of the time exposure to DMSO and sucrose, and cryoprotectants concentrations, followed by extraction-dilution in sucrose without freezing made it possible to study chemical toxicities. Variation of cryoprotectant concentrations followed by immersion in liquid nitrogen, thawing, extraction, and dilution made it possible to choose optimal conditions for vitrification. The sucrose concentration upon extraction after freezing and thawing which was lower than that during soaking enhanced the oocyte survival rate as did the choice of duration and temperature of soaking. No parthenogenetical activation of these unfertilized ovum was observed. This study indicates that with a certain combination of DMSO and sucrose concentrations up to 80% of morphologically intact human oocytes can be recovered after rapid freezing and thawing

Evaluation of a synthetic serum substitute to replace fetal cord serum for human oocyte fertilization and embryo growth in vitro.

A comparison was made between a serum substitute. UltroSer G (Gibco, Ghent, Belgium) (2%) (medium B) and 10% human fetal cord serum (medium A), as regards their ability to support 1-cell and 2-cell mice embryo development in vitro. Sixty percent and 56% of the 1-cell embryos reached the expanded blastocyst stage when cultured in media A and B, respectively. Eighty-four percent and 88% of 2-cell embryos reached the expanded blastocyst stage when cultured in media A and B, respectively. A prospective randomized study was then performed to evaluate this synthetic serum substitute in human in vitro fertilization. Among 141 ovum pick-up (OPU), oocytes retrieved in 74 cases were processed in medium A and oocytes retrieved in 67 others in medium B. In media A and B, the fertilization rate was 67% and 44.3% respectively, and the pregnancy rate/OPU 23% and 9%, respectively. The pregnancy rate/transfer was 28.8% and 12.2% respectively, and the implantation rate/transferred embryo 9.5% and 4.2%. In the human sperm survival assay, the vitality and residual motility after 24 hours of incubation were significantly lower in medium B. In conclusion, UltroSer G successfully sustained the development in vitro of mouse embyros. However in human, it reduced sperm survival, oocyte fertilization, and embryo viability

Development of an algorithm which generates functional floor plans for residential buildings based on modular construction

Dissertação de Mestrado Integrado em Engenharia Civil apresentada à Faculdade de Ciências e Tecnologia da Universidade de CoimbraUm dos objetivos fundamentais da arquitetura e da engenharia civil é a construção e reabilitação de edifícios habitacionais. Estas áreas colaboram entre si para desenvolver soluções que satisfaçam os desejos do cliente incluindo as preferências estéticas e os requisitos técnicos legais, e, obviamente, tendo em conta a segurança, funcionalidade e o conforto da construção. Isto poderá ser atingido através dum processo iterativo que usualmente começa por um leque pequeno de soluções, das quais uma é escolhida e seguidamente modificada até se obter o projeto final da habitação. Este procedimento demora habitualmente um tempo substancial. Por outro lado, a construção modular constitui um método inovador baseado num conceito de casa adaptável e flexível, que consiste na organização de soluções uniformes em bloco, pré-fabricadas em aço enformado a frio, numa grelha organizacional de múltiplos de uma unidade básica, quase como se de um jogo de Lego® se tratasse. Esta tecnologia é altamente sustentável e permite modificações na construção final durante o seu período de vida útil. Por fim, os custos são minorados e a relação custo-benefício é majorada. Assim, a presente dissertação objetiva o desenvolvimento dum algoritmo que gere várias soluções de plantas de arquitetura baseado em módulos arquitetónicos de construção modular previamente estudados. Este objetivo foi atingido através da implementação em Java® deste algoritmo que testa e combina 3 módulos de arquitetura modular até encontrar todas as soluções que obedeçam a determinadas restrições.One of the fundamental objectives of architecture and civil engineering is to construct and rehabilitate residential buildings. Both parties collaborate in order to provide solutions that fit the client’s desires, satisfy legal requirements, while granting aesthetic preferences and, obviously, are functional, safe and satisfy serviceability requirements. This may be accomplished by an iterative process which commonly starts from a spectrum of a few solutions, where one is chosen and arranged until achieving the final building design. This process takes a substantial amount of time. On the other hand, modular construction presents an innovative constructive method based on a flexible and adaptive housing concept, which consists on arranging uniform modular solutions, pre-fabricated on cold formed steel, on an organizational grid of multiple numbers of a basic unit, almost as if it was a Lego® game. This technology is highly sustainable and allows modifications on the solutions during its life cycle. Last but not least, costs are diminished and energy efficiency is improved. Therefore the objective of the present dissertation is the development of an algorithm that generates multiple floor plan design solutions based on previously studied architectural modules of modular construction. This objective was accomplished by implementing the algorithm in Java® which tests and combines 3 modules of modular construction until it reaches every solutions that obey specific constraints

Prediction of individual response to controlled ovarian hyperstimulation by means of a clomiphene citrate challenge test.

A clomiphene citrate (CC) challenge test was carried out in 114 patients to evaluate the capacity of this test to predict the patient's individual response to controlled ovarian hyperstimulation (COH) performed with a gonadotropin-releasing hormone agonist and human menopausal gonadotrophins (hMG) for in vitro fertilization. The sum of follicle-stimulating hormone measured before and after CC intake, is the parameter that correlated best with subsequent response to COH. The upper limit of the reference value for this parameter, established by considering the CC challenge test performed on 26 patients who became pregnant, was 26.03 mIU/mL. Twenty patients who presented a CC challenge test result above the reference value were compared with patients with a normal test result. For these 20 patients, COH required more hMG and was cancelled in 25% of the cases (instead of 1% in the control group). The number of follicles aspirated, oocytes retrieved, and embryos obtained were on average six times lower than in patients with a CC challenge test result within the reference value, and no pregnancy was obtained. We concluded that CC challenge test provides a reliable individual prognosis for the ovarian response to COH

Micromanipulation of mouse gametes with laser microbeam and optical tweezers.

Micromanipulation of mouse gametes with a commercially available compact laser microbeam system was studied. Both the normal in-vitro fertilization (IVF) group and the laser zona dissection (LZD) group were tested under normal (2 x 10(6) motile spermatozoa/ml) and low (500,000 motile spermatozoa/ml) insemination conditions. Subzonal insemination (SUZI) was also tried in a small group of gametes and the results were compared with those of the low insemination groups. Fertilization rates and blastocyst formation rates for the IVF and the LZD-treated groups were respectively 53 and 60% and 60 and 78%, which were not significantly different. However, under low insemination conditions, the results were significantly better in the LZD-treated group (58% fertilization rate and 83% blastocyst formation rate) compared to the results of the IVF group (33 and 48%) (P < 0.05). The SUZI-treated group showed the lowest fertilization rate (18%). No significant difference between the LZD and the IVF group was observed with respect to parthenogenetic activation. LZD has a beneficial effect on fertilization rates in cases of reduced sperm quality

Early increase in pulmonary vascular reactivity with overexpression of endothelin-1 and vascular endothelial growth factor in canine experimental heart failure

SCOPUS: ar.jFLWINinfo:eu-repo/semantics/publishe