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In this paper, we will report a read-only spin valve that has a trackwidth of 1.4 /spl mu/m, a read gap of 0.23 /spl mu/m, and with a stripe height of 0.75 /spl mu/m. It had a corrosion resistant exchange pinning layer, Co/sub 90/Fe/sub 10//FeMnRh, that provided an exchange bias of 225 Oe. It produces a very stable signal and a normalized amplitude of 1 mv//spl mu/m/(memu/cm/sup 2/). Furthermore its asymmetry is lower that 6%. The /spl Delta/R/R of the spin valve film was 5.2% with the following structure: Ta(5 nm)/NiFe(2 nm)/Co/sub 90/Fe/sub 10/(5 nm)/Cu(2.8 nm)/Co/sub 90/Fe/sub 10/(1.2 nm)/NiFe(2 nm)/FeMnRh(10 nm)/Ta(5 nm). The spin valve heads were soaked for 96 hours in a corrosion test chamber that was operated at a temperature of 85 C and a humidity of 85%. The sensor element, the exchange bias film, the hard magnetic longitudinal bias, and the conducting leads were free from corrosion after the corrosion test. Furthermore the spin valve read-only heads were electro-migration tested in an oven operated at 120/spl deg/C, and the heads survived with the operating current up to 9 ma.

We have developed Soft-Adjacent-Layer (SAL)-biased MR head products with two types of permanent magnet (PM) domain stabilization schemes, namely, abutted and overlaid. Both types of MR heads are capable of achieving recording density of 500 Mb/in/sup 2/ with linear bit densities ranging from 100-118 kbpi. While transfer curves with a transverse sweeping field showed similar behavior for both PM schemes, the overlaid structure has a large hysteresis in its transfer curve under a longitudinal sweeping field while the abutted junction was hysteresis free. Micromagnetic modeling showed that the hysteresis for the overlaid scheme arises from the varying field response of the MR element in the active region, under the leads and under the PM. Magnetic test shows that the abutted MR head with a PM defined TW had a slower rise in sensitivity and had an effectively narrower magnetic track width. On the other hand, the overlaid MR head with an active region defined by the leads with MR under them has a steeper rise in sensitivity, a broadened magnetic read track and side readings.

Pseudo-Contact magnetic recording sliders remain in contact with the disk even at operating speeds. The continuous contact can cause wear of the interface that might eventually lead to failure of the drive. In order to evaluate the long term reliability, precise measurements of the slider wear are necessary. In this paper, a new method of measuring the depth and location of wear on the slider is described. Fiduciary marks are created on the slider air-bearing surface using a focused ion beam (FIB). These FIB marks are characterized using an AFM before and after a wear test. The technique allows measurement of wear depths within an accuracy of /spl plusmn/1 nm. Some additional techniques for detecting slider wear are described.

Uterine secretion from the endometrial glandular epithelium provides optimal conditions for early embryonic development. The uterine milk protein (UTMP), a member of the serine proteinase inhibitor superfamily, has been demonstrated to be a major progesterone-induced glycoprotein secreted by the endometrium during pregnancy. Previous transcriptomic analysis revealed that UTMP was highly abundant at estrus in the bovine endometrium (Bauersachs et al. 2005 J. Mol. Endocrinol. 34, 889–908). Here we describe a detailed characterization of UTMP mRNA expression at several time points during the bovine estrous cycle and the pre-implantation period. Simmental heifers were monitored with respect to serum progesterone (P4) and estradiol-17β (E2), and slaughtered at estrus or 3.5, 12, 15, or 18 days after estrus, or at Day 15 or 18 of pregnancy (n = 4 per group). The uterus was divided into corpus and caudal, middle and cranial parts of the ipsilateral uterine horn for sampling of intercaruncular endometrium. In addition, effects of steroid hormones were investigated by stimulating an endometrial cell culture obtained from Day 8 animals (n = 4) with physiological doses of P4 or E2. In all cases, UTMP mRNA was quantified by real-time RT-PCR. Pronounced changes of UTMP mRNA abundance were detected during the estrous cycle. Expression was highest at estrus, followed by a remarkable decrease at Day 3.5. There was no difference between pregnant and non-pregnant animals at Day 15. Cycling animals displaying a high P4 and low E2 content (P4 > 2 ng mL-1 and E2 < 1 pg mL-1) revealed a lower expression of UTMP at Day 18 compared to the pregnant heifers, whereas animals at Day 18 progressing toward estrus (P4 < 1.5 ng mL-1 and E2 > 3 pg mL-1) exceeded the mRNA expression of the pregnant group. Following stimulation with estradiol-17β, the in vitro UTMP transcripts increased significantly. These results indicate that two different interfering stimulatory events might take place. While estradiol-17β appeared to increase UTMP mRNA expression at estrus, a second factor, most probably embryo-derived or embryo-induced, is assumed to be responsible for the UTMP rise during early pregnancy. The distinct gradient from the cranial uterine horn to the corpus at estrus was less pronounced at Day 3.5 and absent at Days 12, 15, and 18, pointing toward functional implications regarding the passing gametes, particularly sperm. An antibody raised against bovine UTMP will further validate the observed mRNA regulations on the protein level. In conclusion, bovine UTMP seems to play a decisive role for precise cyclic regulation of the bovine uterine milieu and during early embryo-maternal communication. This work was supported by the DFG FOR 478.

Nitric oxide synthases (NOS) are involved in a large number of biochemical processes. By generating inorganic free NO radicals, which are important modulatory agents, NOS are supposed to contribute to the regulation of mammalian reproduction. We have, therefore, studied the expression and localization of inducible NOS (iNOS) in the bovine oviduct during the estrous cycle. Simmental heifers were synchronized and slaughtered at Days 0, 3.5, 12, or 18 after standing heat. Bovine oviduct epithelial cells (BOEC) of ampulla and isthmus were collected separately for ipsi- and contralateral oviducts, as determined by the ovulatory follicle or the functional corpus luteum. In addition, a BOEC in vitro suspension culture from heifers of day 3.5 was established and stimulated with physiological doses of progesterone and estradiol-17β (10 ng/mL and 10 pg/mL, respectively). Total RNA was extracted and iNOS mRNA was absolutely quantified using real-time RT-PCR. For statistical analysis, the MIXED procedure of the SAS program package (SAS Institute, Inc., Cary, NC, USA) was used to model the experimental design (n = 4). Differences were indicated as statistically significant in the case of P < 0.05. Furthermore, immunoreactive iNOS protein was localized on serial oviductal cryosections. Transcripts of iNOS mRNA were detected in bovine oviducts throughout the estrous cycle. Since the level of 18S rRNA did not differ significantly the data were not normalized. Positive immunohistochemical staining for iNOS in the luminal epithelium gave evidence for the presence of iNOS protein in the bovine oviduct. At estrus (Day 0) and Day 18, the mRNA abundance of iNOS in epithelial cells of both ipsi- and contralateral isthmus was significantly lower than in epithelial cells of the ampulla. At Day 3.5, iNOS expression was significantly reduced in the contralateral but not the ipsilateral isthmus, whereas the abundance in the ipsilateral isthmus reached levels similar to those in the ampulla. At Day 12 the mRNA abundance was low without region specific differences. A down-regulation of iNOS could be associated with an accelerated oviductal transport due to higher contractility and increased ciliary motion in the luminal epithelium of the oviduct. This might be of special importance around ovulation time for gametes as well as for the formation of a homogeneous oviductal fluid. A modulated expression pattern of iNOS during the estrous cycle points towards a possible hormonal regulation. Preliminary in vitro results showed that in BOEC iNOS responded to progesterone, while no such up-regulation was observed after estradiol-17β stimulation. As Day 3.5 coincides with early embryonic development shortly after fertilization, the possible progesterone-dependent increase of iNOS transcripts in the ipsilateral isthmus might lead to a necessary local quiescence. Due to region-specific different transcript abundance, the presence of a local NO-system in the bovine oviduct can be postulated. Therefore, these findings point out a possible important role of iNOS in the oviduct for reproductive success. This work was supported by the DFG Ei 296/10-1 and the Ev. Studienwerk eV.

Bovine oviduct epithelial cells (BOEC) are difficult to culture without dedifferentiation. Frequently observed changes in morphology during culture suggest that gene expression patterns are affected as well. We explored a novel short-term culture system for BOEC – suitable for co-culture experiments with embryos – and evaluated the cells with respect to morphological criteria, candidate gene expression, and hormone responsiveness. Simmental heifers were slaughtered on Day 3.5 after standing heat and BOEC were obtained by squeezing along the ampulla with forceps. The cell sheets were separated mechanically by repeated passages through syringes and pipetting, and recovered by sedimentation. Cells from the ipsi- and contralateral oviduct were cultured separately at a density of 106 cells per well in 24-well plates with 800 μL TCM-199 supplemented with 2% OCS (estrous cow serum, as used in embryo culture) or CS 3.5 (cow serum, Day 3.5 after standing heat, adequate to the cycle stage in which cells were obtained) and 0.25 mg/mL gentamicin. For cell counting, an aliquot was further disaggregated by passing 15 times through a 30-gauge needle to achieve a single-cell suspension. Culture took place at 38°C in a humidified atmosphere of 5% CO2 in air. Cells were examined by light microscopy at seeding and after 6, 12, 24, and 48 h. Cell aggregates showed a worm-like structure, displaying numerous vigorously beating cilia on their surfaces throughout the culture period. Trypan blue staining indicated that cells contained in aggregates were viable while single cells stained predominantly positive (non-viable). The purity of the epithelial cell culture was >95%, as determined by immunohistochemistry using antibodies against vimentin and cytokeratin. For electron microscopic investigations, BOEC were sampled at seeding and after 24 h in culture. Cultured BOEC showed a morphology highly similar to that of BOEC in vivo. Both secretory cells with numerous secretory granules and mitochondria, and ciliated cells with long, well developed and actively moving kinocilia were visible. RT-PCR data for candidate genes (ERα, ERβ, HMGCR, PHGPx, PR) obtained from BOEC samples at seeding and after 6, 12, 24, and 48 h in culture showed that gene expression was stable for the majority of transcripts after 6 h in culture. There was no significant difference between cells cultured with OCS or CS 3.5 and no difference between cells obtained from the ipsi- or contralateral oviduct. Estradiol-17β (E2, 10 pg/mL) or progesterone (P4, 10 ng/mL) stimulation showed that the cultured BOEC are able to respond to hormonal signals in a manner similar to their reaction in vivo (Ulbrich et al. 2003 J. Steroid. Biochem. Mol. Biol. 84, 279–89). Progesterone receptor mRNA was up-regulated by E2 and estrogen receptor β mRNA was up-regulated by P4. The culture system for bovine oviduct epithelial cells thus provides an adequate tool to investigate mechanisms of the embryo-maternal communication in cattle. This work was supported by the Deutsche Forschungsgemeinschaft (Research Unit “Mechanisms of Embryo-Maternal Communication”; FOR 478/1).