Embryonic, genetic and clinical outcomes of fresh versus vitrified oocyte: A retrospective cohort study

Objective:To compare embryonic development,ploidy status and clinical outcomes between fresh and frozen-thawed oocytes.Methods:This retrospective cohort study evaluated 83 fertilization cycles including both fresh and frozen oocytes from 79 patients at the HP Fertility Center of Hai Phong International Hospital of Obstetrics and Pediatrics in Vietnam.The patient underwent several ovarian stimulation cycles to accumulate a certain number of oocytes that would be vitrified.In the last oocyte retrieval,all patient’s oocytes including both frozen and fresh would be fertilized.The outcomes included the rates of oocyte survival,cleavage embryo,blastocyst,ploidy status,pregnancy,biochemical pregnancy and clinical pregnancy.Results:The oocyte survival rate after thawing was 96.5%.No statistically significant difference was found when comparing fresh and frozen oocytes regarding fertilization rate(78.1%vs.75.5%,P=0.461),usable cleavage embryo rate(86.9%vs.87.2%,P=0.916)but usable blastocyst rate was found higher statistically in the frozen oocyte group(44.4%vs.54.0%,P=0.049).The percentages of euploid,aneuploid and mosaic embryos between the fresh group and the vitrified group had no significant differences(33.8%vs.31.6%,P=0.682;51.0%vs.54.2%,P=0.569;15.2%vs.12.4%,P=0.787;respectively).The rates of pregnancy,biochemical pregnancy and clinical pregnancy had no statistical difference(68.8%vs.64.8%,P=0.764;12.5%vs.3.6%,P=0.258;37.5%vs.46.4%,P=0.565).17 Mature oocytes are the minimum to have at least one euploid embryo.Conclusions:Oocyte vitrification does not affect embryonic,genetic and clinical results.The number of mature oocytes should be considered for fertilization in some cases.

Comparison of Morphological Microstructure of Vitrified and Normal Shoots of Aronia melanocarpa Elloit

The Aronia melanocarpa El oit was used as test material. The microstruc-ture of normal and vitrified shoots and the characteristics of their stomas on leaf surface were compared by paraffin section and leaf epidermis-tearing method. The results showed the palisade tissue of Aronia melanocarpa El oit consists of 2-3 lay-ers of cells. The stomas on lower epidermis cave in, and are smal and dense. There are abundant vessels and sieve tubes in stems. ln contrast, the main veins of vitrified shoots are unobvious, messy and irregular. The boundary between pal-isade tissue and spongy tissue is not obvious. The stomas open circularly and bigly. The stems are swel ing and thick, but the pith parenchyma cells are broken.

Effect of ZrO_2 Content on the Properties of Diamond Grinding Wheel Vitrified Bond

The effect of ZrO2 content on the performance of vitrified bond was discussed. The results showed that when the ZrO2 content was less than 2 mol%, Zr4＋ could enter into the glassy network as mending nets and agglomeration composition. In this case, with the increasing of ZrO2, the vitrified bond＇s bending strength increased and the expansion coefficient decreased. It was also found that the wetting angle between the vitrified bond and diamond got small because Zr4＋ was enriched on diamond surface. When ZrO2 content was more than 2 mol%, a part of ZrO2 existing in vitrified bond as ZrO2 particles played the role in nucleating agents and promoting the separation of spodttrnene. When ZrO2 content was 3 mol%, the bending strength of the vitrified bond reached its maximum of 128 MPa and the wetting angle with the diamond reached its minimum of 37.6°.

New Vitrified Bond Diamond Grinding Wheel for Grinding the Cylinder of Polycrystalline Diamond Compacts

In this work, a kind of new vitrified bond based on Li2O-Al2O3-SiO2 glass ceramics was used to bond the diamond grains, which is made into grinding wheel and the cylindrical grinding process of polycrystalline diamond compacts （PDCs） by using the new vitrified bond diamond grinding wheel was discussed. Several factors which influence the properties of grinding wheel such as amount of vitrified bond and the kinds and amount of stuff in grinding wheel were also investigated. It was found that the new vitrified bond can firmly combine diamond grains, when there are only diamonds and vitrified bond in the structure of grinding wheel, the longevity of the grinding wheel is about 2.5-3 times as that of resin bond grinding wheel for processing PDCs. The grinding size precision of PDCs can be improved from 4-0.03 mm to 4-0.01 mm because of larger Young＇s modulus of vitrified bond than resin bond. The grinding time of a PDC product can be 1.75-2.0 min from 3.25-3.5 min, so this kind of grinding wheel can save much time for processing PDCs. Also, there is hardly noise when using this new vitrified bond diamond grinding wheel to process PDCs. The amount of vitrified bond in grinding wheel influences the longevity of grinding wheel. When the size of diamond grains is 90-107 μm, the optimal amount of vitrified bond in grinding wheel is 21% （wt pct）. When the amount of vitrified bond exceeds 21%, there are many pores in grinding block, which will decrease the longevity of grinding wheel. The existence of addition stuff such as Al2O3 or SiC can reduce the longevity of grinding wheel.

Influence of Li2O Addition on the Performance of Vitrified Bond and Vitrified Diamond Composites

In order to develop high-performance diamond wheels,the vitrified bond with different contents of Li2O addition and corresponding diamond composites were prepared.The experimental results show that the addition of a small content of Li2O leads the formation of the mullite phase in vitrified bond.When the Li2O content is 3wt%,the mullite content in the vitrified bond reaches the maximum.Whereas,the vitrified bond turns into a pure glass phase when the Li2O content further increases to 5wt%.The softening temperature of vitrified bond,wetting angle between the vitrified bond and the diamond film decrease with the increasing of the Li2O content.The softening point of the vitrified bond with 5wt% Li2O is 537 ℃ and the contact angle is 32°,which are 44 ℃ and 44° lower than those of the sample without Li2O.The CTE (coefficient of thermal expansion),the flexural strength and hardness of the diamond composite sample first increase and then decrease with the increasing of the Li2O content.When the Li2O addition is 3wt%,the flexural strength and hardness of the composites reaches the maximum values of 93 MPa and 98 HRB,respectively,which are 43.1% and 12.6% higher than those of the sample without Li2O.

Effects of nano-AlN on phase transformation of low temperature vitrified bond during sintering process

The effects of nano-AlN and sintering temperature on bending strength and wear resistance of low temperature vitrified bond for diamond grinding tools were studied. Furthermore, the phase transformation during sintering process was investigated by means of thermo-gravimetric analysis (TG), differential thermal analysis (DTA) and X-ray diffraction (XRD). The results show that the higher bending strength and wear resistance of low temperature vitrified bond are obtained by adding nano-AlN in bonds and sintering at optimum temperature. Nano-AlN added in bonds promotes the crystallization during sintering process and refines the grain sizes of crystalline phase.

Effect of Aluminum Addition on Microstructure and Properties of SiO_2-B_2O_3-Al_2O_3-CaO Vitrified Bond

Influence of aluminum addition on the structures and properties of SiO_2-B_2O_3-Al_2O_3-CaO vitrified bond at low sintering temperature and high strength was discussed. FTIR and XRD analyses were used to characterize the structures of the basic vitrified bond with different contents of aluminum. The bending strength and the thermal expansion coefficients were also tested. Meanwhile, the microstructures of composite specimens at sintering temperature of 660 ℃ were observed by scanning electron microscope（SEM）. The experimental results showed that the properties of vitrified bond with 1wt% aluminum were improved significantly, where the bending strength, Rockwell hardness, and thermal expansion coefficient of the vitrified bond reached 132 MPa, 63 HRB, and 6.73×10^（-6） ℃^（-1）, respectively.

Improvement of cortical granules migration andin vitro embryo production of vitrified bovine oocyte by 9-cis retinoic acid

Objective:To reveal the effects of 9-cis retinoic acid (RA) on cortical granules (CGs) migration andin vitro embryo production (IVP) rate in meiosisⅡvitrified bovine oocyte. Methods:Followingin vitro maturation (IVM) in a medium containing 5 nM of 9-cis-RA, 60 oocytes were vitrified and then thawed. Then, half of them were evaluated for CGs migration and the other half were used for in vitro fertilization and IVP (on day 3). In addition, the other 60 oocytes were considered as the control group, which did not receive RA in IVM medium. The data were presented to one way analysis of variance (ANOVA) and Duncan's test.Results:Results showed that IVP rate (4-8 cells embryos) was significantly (P<0.05) higher than the control group when RA had been added to IVM medium. Furthermore, the presence of RA in IVM medium improved the rate and mode of CGs migration so that the rate of oocytes that had completed CGs migration in the group, which had received RA, was significantly higher than the control group.Conclusions:This study shows that presence of RA in IVM medium enhances the developmental competence and CGs distribution of meiosisⅡvitrified bovine oocyte. Therefore, adding RA in IVM medium can decrease the ultrastructural changes during vitrification and can improve the efficiency of bovine oocyte vitrification.

the Shandong Electric Power Engineering Consulting Institute science and technology project(Grant No.37-K2014-33).

The damage caused by thermal stress during rewarming vitrified biosamples is one of the major obstacles for clinical purposes.Magnetic warming is a highly effective approach to overcome this hurdle and can achieve rapid and spatially homogeneous heating.The current research investigates the effects of magnetic warming on the histological and biomechanical properties of the vitrified umbilical arteries(UAs)through experiments and simulation.The results of experiments show that,for the case of magnetic warming comparing with the conventional water bath,magnetic warming presents better preservation of extracellular matrix(ECM),collagen fibers,elastic fibers,and muscle fibers of the umbilical artery.There is no significant difference between magnetothermal and fresh UAs(p>0.05)in the elastic modulus and the ultimate stress.The theoretical results reveal that the maximum temperature difference Tmax inside the biosample is 1.117±0.649℃,and the maximum thermal stressmax is 0.026±0.016 MPa.However,for the case of conventional water bath,Tmax is 32.342±0.967℃andmax is 1.453±0.047 MPa.Moreover,we have arrived at the same conclusion by simulation as theoretical calculation have.Therefore,magnetic warming can effectively reduce the thermal stress damage of biological samples during the warming period due to more uniform and rapid warming.These results confirm that magnetothermal can significantly improve the mechanical properties of large size cryopreserved tissues or organs such as UAs.

TRANSLUCENT GREEN, an ERF Family Transcription Factor, Controls Water Balance in Arabidopsis by Activating the Expression of Aquaporin Genes

Water is the most abundant molecule in almost all living organisms. Aquaporins are channel proteins that play critical roles in controlling the water content of cells. Here, we report the identification of an AP2/EREBP family transcription factor in Arabidopsis thaliana, TRANSLUCENT GREEN （TG）, whose overexpression in transgenic plants gave enhanced drought tolerance and vitrified leaves. TG protein is localized in the nucleus, binds DRE and GCC elements in vitro, and acts as a transcriptional activator in yeast cells. Microarray analysis revealed a total of 330 genes regulated by TG, among which five genes encode aquaporins. A transient expression assay showed that TG directly binds to the promoters of three aquaporin genes, such as AtTIP1;1, AtTIP2;3, and AtPIP2;2, indicating that TG directly regulates the expression of these genes. Moreover, overexpression of AtTIP1;1 resulted in vitrified phenotypes in transgenic Arabidopsis plants, similar to those observed in TG overexpression lines. Water injection into wild-type leaves recapitulated the vitrified leaf phenotypes, which was reversed by cutting off the water supply from vascular bundles. Taken together, our data support that TG controls water balance in Arabidopsis through directly activating the expression of aquaporin genes.