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Recently, 3-D Digital Image Correlation (DIC) is widely applied to the reliability analysis of electronic packages, which particularly characterizes the in-situ deformation of ball grid array (BGA) packages. During the image correlation procedure, many parameters influence the accuracy and data integrity of measurement result. Facet (subset) size is the principal parameter and has been studied with much effort. However, the solder balls, which are built on the substrate surface, make the scenario different with the conventional 3-D DIC experiment for the planar samples. The undulant surface generates more obstacles for the successful image correlation. In order to summarize an effective solution of 3-D DIC measurement method for solder balls attached packages, camera angle, facet size and facet step are studied with different BGA packages and different stereoscopic camera systems to achieve the best correlation quality. Also, a novel surface treatment method is introduced to guarantee the surface speckles are generated uniformly on the fluctuant surface. [ABSTRACT FROM AUTHOR]

Abstract: Natural resistance-associated macrophage protein 1 (NRAMP1) containing 548 amino acids (AA) and 12 transmembrane domains (TMDs) is localized in membranes of lysosomes. Our study aimed to investigate the targeting motifs of NRAMP1 by expressing GFP-tagged full-length and truncated NRAMP1 proteins and overlapping with the lysosomal marker Lamp1-RFP in Chinese hamster ovary (CHO) cells. The NH2-terminal amino acids 73–140 region including TMD2 was essential for NRAMP1 lysosomal targeting. The AA.263–334 region containing the tyrosine-based motif 327YAPI330 targeted NRAMP1 into lysosomes. Additionally, two internal signal peptides AA.451–483 and AA.489–522 were identified as lysosomal targeting motifs. Taken together, NRAMP1 consists of multiple targeting motifs for trafficking into lysosomes. [Copyright &y& Elsevier]

Despite recent advances in semantic manipulation using StyleGAN, semantic editing of real faces remains challenging. The gap between the W space and the W+ space demands an undesirable trade-off between reconstruction quality and editing quality. To solve this problem, we propose to expand the latent space by replacing fully connected layers in StyleGAN's mapping network with attention-based transformers. This simple and effective technique integrates the two spaces mentioned above and transforms them into one new latent space called W++. Our modified StyleGAN maintains the state-of-the-art generation quality of the original StyleGAN with moderately better diversity. But more importantly, the proposed W++ space achieves superior performance in both reconstruction quality and editing quality. Besides these significant advantages, our W++ space supports existing inversion algorithms and editing methods with only negligible modifications thanks to its structural similarity with the W/W+ space. Extensive experiments on the FFHQ dataset prove that our proposed W++ space is evidently preferable to the previous W/W+ space for real face editing. The code is publicly available for research purposes at https://github.com/AnonSubm2021/TransStyleGAN. [ABSTRACT FROM AUTHOR]

An energy-based 3-D model was created to simulate the solder joint formation of the chip capacitor during reflow. The surface tension ($F_{s}$) and hydrostatic force ($F_{h}$) of molten solder and the gravitational force ($F_{g}$) of a chip capacitor and solder paste were considered in this 3-D model. The initial geometry of solder joint is evolved into an equilibrium shape to minimize the internal energy of molten solder. In this study, we investigated the effect of various design parameters, such as solder paste volume, copper pad dimension, and component height on the solder joint shape of capacitor. Chip capacitor C1005 and C0603 with SAC305 solder paste and copper pads with electroless nickel immersion gold (ENIG) surface finish were used as examples. Actual capacitor samples were cross-sectioned and inspected to validate the simulation results from the 3-D model. Moreover, the self-alignment of the chip capacitor was studied in this work. The component self-alignment will affect the accuracy of component assembly and significantly affects the chip capacitor solder joint formation. Simulations were performed to address the mechanism of chip capacitor self-alignment during reflow soldering. The effect of solder paste volume on the capacitor self-alignment was summarized. The result showed relatively more solder paste that can improve the capacitor self-alignment because of the bigger restoring force generated by the molten solder. The inconsistency of solder paste volumes at the two terminations will cause the capacitor to offset from the center. It is found that the misalignment of capacitor C1005 can be reduced to $\pm 30~\mu \text{m}$ in component-length direction and $\pm 30~\mu \text{m}$ in component-width direction by the optimization of solder paste volume. The self-alignment is better in component-width direction than component-length direction. An extensive number of experimental studies were performed to develop a data-driven prediction model so that the manufacturing cost during trial tests can be reduced. In the experiments, the chip capacitors were placed intentionally with some initial offsets and their positions were measured before and after the reflow. Simulation results showed good agreement with the experimental data. [ABSTRACT FROM AUTHOR]

Staphylococcus aureus is a food‐borne pathogen that quickly forms biofilm on meat contact surfaces and thus poses a serious threat to the safety of the meat industry. This study evaluated the attachment, survival, and growth of S. aureus biofilm with exposure to environmental factors in the meat industry by simulated ready‐to‐eat (RTE) cooked beef product contamination scenarios. The results indicated that the meat‐borne S. aureus biofilm formation dynamic could be divided into four different phases: initial adhesion (4–12 h), exponential (12–24 h), slow growth (1–3 days), and stationary (3–7 days). Meat‐borne S. aureus has strong adhesion and biofilm formation ability, and its biofilm exhibits persistence, high‐intensity metabolic activity, aerotaxis, and strain heterogeneity. This study has also demonstrated that in the long‐term existence of meat‐borne S. aureus biofilm on stainless steel and plexiglass surfaces (>7 days, 7.2–8.8 log CFU/cm2), expose to RTE cooked beef products, may cause it to become high‐risk contaminated food. Meat‐borne S. aureus that forms a dense and rough concave‐convex in the shape of biofilm architecture was observed by scanning electron microscopy, consisting of complex components and adhesion of living and dead cells. This was further confirmed by the meat‐borne S. aureus biofilm on the stainless steel surface by attenuated total reflectance Fourier transformed infrared spectroscopy, and the dominant peaks in biofilm spectra were mainly associated with proteins, polysaccharides, amino acid residues, and phospholipids (>50%). These findings may help in the identification of the main sources of contamination within the meat industry and the subsequent establishment of strategies for biofilm prevention and removal. Practical Application: This study revealed the meat‐borne S. aureus biofilm formation mechanism and found that it exhibited strong colonization and biofilm‐forming ability, which can persist on the contact surfaces of ready‐to‐eat beef products. These initial findings could provide information on the behavior of meat‐borne S. aureus biofilm attached to meat contact surfaces under conditions commonly encountered in meat environments, which help to support the determination of the main sources of contamination within the meat industry and the subsequent establishment of strategies for biofilm prevention and removal. It was also helpful in controlling biofilm contamination and improving meat safety to minimize it. [ABSTRACT FROM AUTHOR]

Initiation of meiosis is the most difficult aspect of inducing competent oocytes differentiation from human stem cells in vitro. Human induced pluripotent stem cells (hiPSCs) and embryonic stem cells (hESCs) were cultured with follicle fluid, cytokines and small molecule to induced oocyte-like cells (OLCs) formation through a three-step induction procedure. Expression of surface markers and differentiation potential of germ cells were analyzed in vitro by flow cytometry, gene expression, immunocytochemistry, western blotting and RNA Sequencing. To induce the differentiation of hiPSCs into OLCs, cells were firstly cultured with a primordial germ cell medium for 10 days. The cells exhibited similar morphological features to primordial germ cells (PGCs), high expressing of germ cell markers and primordial follicle development associated genes. The induced PGCs were then cultured with the primordial follicle-like cell medium for 5 days to form the induced follicle-like structures (iFLs), which retained both primordial oocytes-like cells and granulosa-like cells. In the third step, the detached iFLs were harvested and transferred to the OLC-medium for additional 10 days. The cultured cells developed cumulus-oocyte-complexes (COCs) structures and OLCs with different sizes (50–150 μm diameter) and a zona pellucida. The in vitro matured OLCs had polar bodies and were arrested at metaphase II (MII) stage. Some OLCs were self-activated and spontaneously developed into multiple-cell structures similar to preimplantation embryos, indicating that OLCs were parthenogenetically activated though in vitro fertilization potential of OLCs are yet to be proved. in vitro maturation of OLCs derived from hiPSCs provides a new means to study human germ cell formation and oogenesis. [ABSTRACT FROM AUTHOR]

This study focused on the development of a gaseous ClO 2 treatment system that contained dry ice that was used to form carbon dioxide (CO 2) and an absorbent pad with sodium chlorite (NaClO 2) solution for ClO 2 gas generation. Furthermore, the effects of ClO 2 gas on the populations of Listeria monocytogenes and the quality properties of table grapes during cold storage were evaluated. The system continuously released the sufficient concentrations of ClO 2 gas to treat berries during 30 d of cold storage. After 20 h of ClO 2 gas treatment, the populations of Listeria monocytogenes decreased from 5.88 log CFU/g to a non-detectable (ND) level. There were no significant (p > 0.05) changes in the color parameters (L*, a*, and b*) of table grapes treated with ClO 2 gas. The firmness, weight, total soluble solids (TSS), and titratable acid (TA) losses of table grapes were significantly (p < 0.05) reduced by ClO 2 gas, while Vitamin C was unaffected. Additionally, the residual ClO 2 of table grapes were <0.5 mg/kg, which is considered a safe level. Overall, the novel gaseous ClO 2 treatment system may be used as an effective intervention technology to improve the safety and quality of table grapes during cold storage. • The gaseous ClO 2 treatment system was developed by reacting CO 2 with NaClO 2. • The system released sufficient ClO 2 gas to treat grape samples during cold storage. • The ClO 2 gas effectively killed L. monocytogenes on samples. • The ClO 2 gas also maintained the quality of samples. • The ClO 2 residues of samples reached a safe level. [ABSTRACT FROM AUTHOR]

Low melting temperature solders are becoming a hot topic in Pb-free solder studies. Among these solders, Sn Bi has attracted more attention because it can not only reduce the energy for reflow, but more importantly, increase the reliability of joints by minimizing warpage. In this study, the board-level reliability of the assembly of BGA components was investigated. Three types of assemblies are compared: mixed (hybrid) Sn-Bi/SAC305 assembly, which is made by soldering BGAs with SAC305 solder balls using eutectic Sn Bi solder pastes so that the low reflow temperature avoids the SAC305 solder joints from being molten; homogeneous eutectic Sn Bi assembly, which is made with solder balls and pastes that are both eutectic Sn-Bi; and homogenous SAC305 assembly as a control group. An accelerated thermal cycling test shows that homogeneous eutectic Sn Bi assembly exhibits the best cycling reliability while the mixed assembly has the shortest fatigue life. The failure mechanism of the mixed assembly is also different from the other two types. Based on the experimental fatigue life results, the parameters of constitutive equation of eutectic Sn Bi are calculated to evaluate the fatigue life of the solder joints. The study shows the better thermal cycling reliability of eutectic Sn Bi assembly and help predict the fatigue life of different assemblies. • A direct comparison of thermal cycling reliability homogeneous Sn Bi joints, homogeneous SAC joints and mixed Sn-Bi/SAC joints. • The constants of constitutive equation of eutectic Sn Bi solder are obtained. • Prediction of fatigue life of homogeneous and mixed solder based on strain energy density distribution. [ABSTRACT FROM AUTHOR]

The reliability assessment of electronic packages demands more accurate and efficient method for evaluating heterogeneous packages and their interconnects in various measurement conditions. The digital image correlation (DIC) method has been fully developed in the last decade. With proper improvement, this work demonstrates that DIC method has the ability to fulfill various experimental tasks and obtain the information for interconnect strain analysis, coefficient of thermal expansion (CTE) characterization, in-plane displacement and out-of-plane warpage quantification within one measurement. To some extent, it serves as a comprehensive tool for electronic packages' reliability assessment. Given that the DIC technique is new to the electronic packaging area, this work illustrates the principle of optical non-contact experiment method and presents several improvements to fit for the measurement on electronic packaging area. With these applications, it is foreseeable that the DIC method will play an important role in the reliability assessment of electronic packages. [ABSTRACT FROM AUTHOR]

Oct4 is an important transcription factor for maintaining self‐renewal and pluripotency of pluripotent stem cells (PSCs). Human OCT4 can be alternatively spliced and generate OCT4a, OCT4b, and OCT4b1. In this study, we discovered the novel Oct4 variants of Oct4b’ and Oct4b1‐3 in mouse PSCs for the first time. The expression of Oct4b variants, especially for Oct4b’, was down regulated along with the downregulation of Oct4a when stem cells were differentiated. We also found four Oct4 translational products that were differentially expressed in mouse PSCs under the different culture conditions. The constructs of Oct4b2 and Oct4b3 could be alternatively spliced into Oct4b and Oct4b’ when constructs were transiently transfected in NIH3T3 cells. Oct4b’ encoded a 189 aa protein, and Oct4b could generate three distinct proteins including Oct4b‐246aa, Oct4b‐221aa, and Oct4b‐189aa. The Oct4b variants could be alternatively translated in different type cells under the control of internal ribosome entry site (IRES) element that is within 5′ upstream sequence of Oct4b. These findings provide new insights into reconsidering Oct4 variants expression and its additional role in maintaining the pluripotency of stem cells. [ABSTRACT FROM AUTHOR]

The estrogen-related receptor b (ESRRB) is an orphan nuclear receptor and targets many genes involved in self-renewal and pluripotency. In mouse ES cells, overexpression of ESRRB can maintain LIF-independent self-renewal in the absence of Nanog. However, the fundamental features of porcine ESRRB remain elusive. In this study, we revealed the expression profiles of ESRRB in both porcine pluripotent stem cells and early stage embryos and dissected the functional domains of ESRRB protein to prove that ESRRB is a key transcription factor that enhanced porcine pluripotent gene activation. Addition of ESRRB into the cocktail of core pluripotent factors Oct4, Sox2, Klf4, and c-Myc (OSKM + E) could significantly enhance the reprograming efficiency and the formation of alkaline phosphatase positive colonies. Conversely, knockdown of ESRRB in piPSCs significantly reduced the expression level of pluripotent genes, minimized the alkaline phosphatase activity, and initiated the porcine induced pluripotent stem cell differentiation. Therefore, porcine ESRRB is a crucial transcription factor to improve the self-renewal of piPSCs. [ABSTRACT FROM AUTHOR]

Previous study showed that expression of epithelial cell adhesion molecule (EpCAM) was significantly upregulated in porcine induced pluripotent stem cells (piPSCs). However, the regulatory mechanism and the downstream target genes of EpCAM were not well investigated. In this study, we found that EpCAM was undetectable in fibroblasts, but highly expressed in piPSCs. Promoter of EpCAM was upregulated by zygotic activated factors LIN28, and ESRRB, but repressed by maternal factors OCT4 and SOX2. Knocking down EpCAM by shRNA significantly reduced the pluripotent gene expression. Conversely, overexpression of EpCAM significantly increased the number of alkaline phosphatase positive colonies and elevated the expression of endogenous pluripotent genes. As a key surface-to-nucleus factor, EpCAM releases its intercellular domain (EpICD) by a two-step proteolytic processing sequentially. Blocking the proteolytic processing by inhibitors TAPI-1 and DAPT could reduce the intracellular level of EpICD and lower expressions of OCT4, SOX2, LIN28, and ESRRB. We noticed that increasing intracellular EpICD only was unable to improve activity of EpCAM targeted genes, but by blocking GSK-3 signaling and stabilizing beta-catenin signaling, EpICD could then significantly stimulate the promoter activity. These results showed that EpCAM intracellular domain required beta-catenin signaling to enhance porcine cell reprogramming. [ABSTRACT FROM AUTHOR]

Porcine induced pluripotent stem cells (piPSCs) retain the enormous potential for farm animal reproduction and translational medicine, and have been reported by many laboratories worldwide. Some piPSC lines were bFGF-dependence and showed mouse EpiSC-like morphology; other lines were LIF-dependence and showed mouse ESC-like morphology. Metastable state of piPSC line that required both LIF and bFGF was also reported. Because bona fide pig embryonic stem cells were not available, uncovering piPSC state-specific regulatory circuitries was the most important task. In this study, we explored the function of Activin-SMAD signaling pathway and its downstream activated target genes in piPSCs. Transcriptome analysis showed that genes involved in Activin-SMAD signaling pathway were evidently activated during porcine somatic cell reprogramming, regardless piPSCs were LIF- or bFGF-dependent. Addition of Activin A and overexpression of SMAD2/3 significantly promoted expressions of porcine NANOG and OCT4, whereas inhibition of Activin-SMAD signaling by SB431542 and SMAD7 reduced NANOG and OCT4 expressions, and induced piPSCs differentiation exiting from pluripotent state. Our data demonstrate that activation of Activin-SMAD signaling pathway by addition of Activin A in culture medium is necessary for maintenance of self-renewal in porcine pluripotent stem cells. [ABSTRACT FROM AUTHOR]

Nanog plays an important role in maintaining the pluripotency of murine and human embryonic stem cells. However, the molecular features and transcriptional regulation of the NANOG gene have not been well investigated in pig. Here, we report, for the first time, that porcine NANOG is encoded by a single exon gene (SEG) mapped on chromosome 1 and has two daughter genes, one pseudogene NANOGP1 on chromosome 5 and one tandem duplicate on chromosome 1. The duplicated pseudogene NANOGP2 has high sequence similarity to NANOG , but does not encode a functional protein due to deletions and in-frame stop codons. The NANOGP1 contains four exons and three introns, but is short of the homeodomain sequence. Transcriptome analysis confirmed that NANOG mRNA in porcine iPS cells is transcribed from the SEG NANOG , but not from NANOGP1 , because the NANOGP1 promoter is highly methylated, as confirmed by global DNA methylation analysis. The NANOG protein encoded by NANOG retains N, H, and C1/W/C2 domains. The H domain is required for nuclear translocation, while the C1/W/C2 domain ensures the NANOG regulatory function. Overexpression of NANOG in porcine embryonic fibroblasts promoted upregulation of its target genes SOX2 , KLF4 , and c-MYC . In conclusion, the functional porcine NANOG that is different in chromosomal structure from mouse and human genes is a single exon gene and encodes the functional NANOG protein that can be specifically regulated by OCT4/SOX2, and can promote the activation of target pluripotent factors in vivo. [ABSTRACT FROM AUTHOR]

It has been demonstrated that naïve and primed pluripotency are determined by different extracellular signals. In this study, we investigated whether intermediate pluripotent states could be available by manipulating the culture condition during the process of generating pig induced pluripotent stem cells (piPSCs). By optimizing the culture condition that efficiently promotes mesenchymal-to-epithelial transition (MET), we found that combination of three growth factors ( LIF, FGF2 and BMP4) and two inhibitors (2i: CHIR99021 and SB431542) could generate an intermediate pluripotent state of piPSCs, which were named as LFB2i-piPSCs. The LFB2i-piPSCs are stable and fulfill all the criteria of pluripotency, including expression of pluripotent genes, differentiation into three germ layers via embryoid bodies in vitro and teratoma in vivo. More importantly, the mRNA-sequencing data showed that LFB2i-piPSCs had a mixed transcriptome of naïve and primed pluripotency, which featured by expressing high levels of SOX2, L- MYC and ESRRB and relatively low levels of POU5F1, KLF4 and NANOG. Small RNA sequencing also demonstrated that LFB2i-piPSCs had a mixed microRNA profile of naïve and primed pluripotency, which featured by expressing high levels of miR-302b/367 cluster and miR-106a/363 cluster, and low levels of most let-7 family members and miR-17/92 cluster. Altogether, the LFB2i-piPSCs represent a stable intermediate pluripotent state with unique transcriptome and microRNA signatures. The LFB2i-piPSCs will provide a new tool to explore the mechanisms of pluripotency and reprogramming on pig species. [ABSTRACT FROM AUTHOR]

Reported pig induced pluripotent stem cells (piPSCs) have shown either a bFGF-dependent state with human embryonic stem cell (ESC) and mouse epiblast stem cell (EpiSC) morphology and molecular features or piPSCs exist in a LIF-dependent state and resemble fully reprogrammed mouse iPSCs. The features of authentic piPSCs and molecular events during the reprogramming are largely unknown. In this study, we assessed the transcriptome profile of multiple piPSC lines derived from different laboratories worldwide and compared to mouse and human iPSCs to determine the molecular signaling pathways that might play a central role in authentic piPSCs. The results demonstrated that the up-regulation of endogenous epithelial cells adhesion molecule (EpCAM) was correlated with the pluripotent state of pig pluripotent cells, which could be utilized as a marker for evaluating pig cell reprogramming. Comparison of key signaling pathways JAK-STAT, NOTCH, TGFB1, WNT and VEGF in pig, mouse and human iPSCs showed that the core transcriptional network to maintain pluripotency and self-renewal in pig were different from that in mouse, but had significant similarities to human. Pig iPSCs, which lacked expression of specific naïve state markers KLF2/4/5 and TBX3, but expressed the primed state markers of Otx2 and Fabp7, share defining features with human ESCs and mouse EpiSCs. The cluster of imprinted genes delineated by the delta-like homolog 1 gene and the type III iodothyronine deiodinase gene ( DLK1-DIO3) were silenced in piPSCs as previously seen in mouse iPSCs that have limited ability to contribute to chimaeras. These key differences in naïve state gene and imprinting gene expression suggests that so far known piPSC lines may be more similar to primed state cells. The primed state of these cells may potentially explain the rare ability of piPSCS to generate chimeras and cloned offspring. [ABSTRACT FROM AUTHOR]

Ground state porcine induced pluripotent stem cells (piPSCs), which retain the potential to generate chimeric animal and germline transmission, are difficult to produce. This study investigated morphological and biological progression at the early stage of porcine somatic cell reprogramming, and explored suitable conditions to increase the induction efficiency of piPSCs. A cocktail of defined transcription factors was used to generate piPSCs. The amphotropic retrovirus, which carried human OCT4 ( O), SOX2 ( S), KLF4 ( K), C-MYC ( M), TERT ( T), and GFP, were used to infect porcine embryonic fibroblasts (PEFs). The number of clones derived from OSKM (4F) and OSKMT (4F+T) was significantly higher than that from SKM (3F) and SKMT (3F+T), suggesting that OCT4 played a critical role in regulating porcine cell reprogramming. The number of alkaline phosphatase-positive clones from a medium with leukemia inhibitory factor (LIF) and basic fibroblast growth factor (bFGF) (M1 medium) was significantly higher than that with insulin and 2i PD0325901/CHIR99021 (M2 medium), indicating that insulin and 2i could not effectively maintain piPSC propagation. In the M1 medium, piPSC lines could not maintain the typical self-renewal morphology on gelatin-coated and Matrigel-coated plates. Without the mouse embryonic fibroblast (MEF) feeder, piPSCs started to simultaneously differentiate. Based on the potential for self-renewal and activation of pluripotent markers, we found that the culture condition of 4F+T plus LIF and bFGF plus MEF feeder promoted PEF reprogramming more efficiently than the other conditions tested here. Two piPSC lines (IB-1 and IB-2) were derived and maintained for up to 20 passages in vitro. [ABSTRACT FROM AUTHOR]

The generation of oocyte-like cells (OLCs) from stem cell differentiation in vitro provides an optimal approach for studying the mechanism of oocyte development and maturation. The aim of this study was to investigate the activation of bone morphogenetic protein 15 gene ( BMP15) during the differentiation of human amniotic fluid stem cells (hAFSCs) into OLCs. After 15 days of differentiation, OLCs with a diameter of 50-60 μm and zona pellucida (ZP)-like morphology were observed. Reverse transcription-polymerase chain reaction (RT-PCR) analysis showed the BMP15 was activated from approximately day 10 of differentiating hAFSCs and thereafter. The reporter construct pBMP15-enhanced green fluorescent protein (EGFP) was transiently transfected into the differentiated hAFSCs and the EGFP expression driven by the BMP15 promoter was positive in the OLCs. Moreover, RT-PCR analysis showed that the oocyte-specific markers including ZP1, ZP2, ZP3, and c-kit were expressed in the differentiated hAFSCs, and the immunofluorescence assay confirmed that the ZP2 was detected in the OLCs. Quantitative RT-PCR revealed that ZP2 and ZP3 were significantly elevated in the differentiated hAFSCs. Further, in the OLCs derived from hAFSCs, the BMP15 promoter directing the EGFP reporter was colocalized with ZP2. Together, these results illustrated that the BMP15 could be used as an oogenesis marker to track hAFSCs differentiation into the OLCs. [ABSTRACT FROM AUTHOR]

Abstract: Myostatin (myostatin) is a member of the transforming growth factor-β superfamily. In this study, we investigated the transcriptional regulation of porcine myostatin expression in C2C12 cells. Sequence analysis of 2kb of the porcine myostatin gene upstream region revealed that it contains 16 E-box motifs. Using a serial deletion strategy, we identified a vital enhancer region between nucleotides −218 and −137 in promoter region of porcine myostatin. Gel-shift assay and deletion analysis result showed F1 site, from nucleotides −206 to −189, was the key element to produce the promoter/nucleus extract complex, which directly interact with transcriptional factor MEF2C. Overexpression of MEF2C increased myostatin promoter activity in dose dependent manner; and whereas introducing of small interfering RNA to MEF2C produced the opposite effect in both myoblasts and myotubes. When endogenous MEF2C was knocked down, the complex of protein/F1 was attenuated, and myostatin mRNA and protein level was also decreased. Thus, we propose that MEF2C could modulate and restrain myogenesis by myostatin activation and myostatin-dependent gene processing in porcine. [Copyright &y& Elsevier]

The octamer-binding transcription factor 4 gene ( Oct4) plays a critical role in maintaining pluripotency during early mammalian embryonic development and self-renewal of embryonic stem (ES) cells. In this study, we cloned the Oct4 cDNA and 2.8-kb regulatory region upstream of the start codon in Guanzhong dairy goat ( Capra hircus). The comparative sequence analysis of Oct4 cDNA showed that it was highly conserved among six mammalian species. The goat Oct4 5′ regulatory regions were homologous to the corresponding regions of Oct4 in other species and were functional in directing the expression of luciferase in mouse P19 embryonic carcinoma cells and mouse J1 ES cells. Furthermore, the methylation levels in the goat Oct4 minimal promoter and proximal enhancer in the fetal genital ridge were lower than those in the heart. Additionally, two processed pseudogenes that shared high homology with goat Oct4 cDNA were identified and characterized. [ABSTRACT FROM AUTHOR]

Abstract: The Bamei gilt is a Chinese native breed located in northwest China, which adapts to the extremely dry and cold environment and is distinguished for its excellent reproductive and maternal characters. To ensure sufficient numbers of embryos for transgenic and nuclear transfer research, hormonal induction of gilt estrus and superovulation may be necessary. The objective of this study was to compare the superovulation effects of equine chorionic gonadotropin (eCG, Group A) and FSH (Groups B–D) in Chinese Bamei gilts. The results show that though eCG could produce more corpora lutea (CL, 14.3) than the control (CL, 9.2), and the FSH treatments had significantly increased the number of CL compared with the eCG treatment. Within the different FSH protocols, the numbers of CL were significantly greater in Groups B (CL, 77.8) and C (CL, 66.8) than in Group D (CL, 42.7), however, ovarian cysts were observed in Groups B and C, but not in Group D. These data suggest that Group D (280IU FSH) is a suitable protocol to facilitate the development of ovarian follicles and increase the number of useful embryos per gilt for embryos recovery. The optimal FSH protocol of superovulation in Bamei gilts appears to be: D13/100IU, D14/80IU, D15/60IU, D16/40IU plus prostaglandin (PG) 0.2mg, D17/hCG 1000IU. [ABSTRACT FROM AUTHOR]

Pluripotent stem cells (PSCs) express telomerase and have unlimited proliferative potential. To study telomerase activation during reprogramming, 3 classes of embryonic stem cell (ESC)-like clones were isolated from mouse fibroblasts containing a transgenic hTERT reporter. Class I expressed few pluripotency markers, whereas class II contained many, but not Oct4, Nanog, and Sox2. Neither class of cells differentiated efficiently. Class III cells, the fully reprogrammed induced PSCs (iPSCs), expressed all pluripotency markers, formed teratomas indistinguishable from those of mESCs, and underwent efficient osteogenic differentiation in vitro. Interestingly, whereas the endogenous mTERT gene expression was only moderately increased during reprogramming, the hTERT promoter was strongly activated in class II cells and was further elevated in class III cells. Treatment of class II cells with chemical inhibitors of MEKs and glycogen synthase kinase 3 resulted in their further reprogramming into class III cells, accompanied by a strong activation of hTERT promoter. In reprogrammed human cells, the endogenous telomerase level, although variable among different clones, was dramatically elevated. Only in cells with the highest telomerase were telomeres restored to the lengths in hESCs. Our data, for the first time, demonstrated that the hTERT promoter was strongly activated in discrete steps, revealing a critical difference in human and mouse cell reprogramming. Because telomere elongation is crucial for self-renewal of hPSCs and replicative aging of their differentiated progeny, these findings have important implications in the generation and applications of iPSCs. [ABSTRACT FROM AUTHOR]

Moisture induced failure is one of the major reliability concerns in electronic packaging. This research provides a comprehensive solution for modeling the moisture induced delamination in electronic packaging during solder reflow. Existing finite element approaches of studying the moisture and vapor pressure induced package delamination issue were discussed, reviewed, summarized and integrated into a systematic approach. This study covered multiple related topics, including diffusion modeling techniques under dynamic thermal loading conditions, fracture mechanics modeling methods for bi-material cracks, and methodologies of applying integrated hygro-thermal-vapor loading conditions. A novel analogy was proposed for applying the combined hygro-thermal-vapor loading in modeling the moisture induced package delamination, which could reduce the users' effort in dealing with the multiple-loading boundary conditions in the fracture mechanics finite element simulation. In the end, the comprehensive finite element approach introduced in this study was implemented to model the moisture induced delamination in a stacked die package during solder reflow. • A comprehensive finite element method for simulating moisture induced delamination in electronic packaging was introduced. • A novel analogy was proposed for applying the combined hygro-thermal-vapor loading conditions in finite element modeling. • Moisture diffusion and delamination behavior of a stacked die package during solder reflow was studied by FEA. [ABSTRACT FROM AUTHOR]

Direct reprogramming is an efficient strategy to convert one cell type to another. In this study, due to the failure of maintaining the undifferentiated state of goat embryotic stem- and induced pluripotent stem-like cells in vitro, we explored an alternative way to directly convert goat fibroblasts to lineage-specific cells. The 'Yamanaka factors' was ectopically expressed in fibroblasts for a short term to situate cells in a metastable state. By culturing with lineage-specific media for 1-2 weeks, the cardiomyocyte-like cells and neurocyte-like cells were generated and confirmed by the quantitative RT-PCR and immunocytochemical staining. The metastable-state cells could also be converted into oocyte-like cells (OLCs) after culturing in media with retinoic acid (RA) and bovine follicular fluid (bFF) for 2-3 weeks. The generated OLCs were surrounded by cumulus granulosa cell-like cells and formed a structure resembling goat cumulus-oocyte complex from ovaries. This primary follicular structure could be developed further in oocyte mature medium and expressed germ cell-specific markers. In addition, we found that the induction efficiency was higher and OLC cell size was bigger in bFF than in RA treatment. Altogether, the direct reprogramming of goat fibroblasts into lineage-specific cells can facilitate stem cell research in domestic animals. [ABSTRACT FROM AUTHOR]