2,023 research outputs found
A novel stepwise micro-TESE approach in non obstructive azoospermia
Background: The purpose of the study was to investigate whether micro-TESE can improve sperm retrieval rate
(SRR) compared to conventional single TESE biopsy on the same testicle or to contralateral multiple TESE, by
employing a novel stepwise micro-TESE approach in a population of poor prognosis patients with non-obstructive
azoospermia (NOA).
Methods: Sixty-four poor prognosis NOA men undergoing surgical testicular sperm retrieval for ICSI, from March
2007 to April 2013, were included in this study. Patients inclusion criteria were a) previous unsuccessful TESE, b)
unfavorable histology (SCOS, MA, sclerahyalinosis), c) Klinefelter syndrome. We employed a stepwise micro-TESE
consisting three-steps: 1) single conventional TESE biopsy; 2) micro-TESE on the same testis; 3) contralateral multiple
TESE.
Results: SRR was 28.1 % (18/64). Sperm was obtained in both the initial single conventional TESE and in the
following micro-TESE. The positive or negative sperm retrieval was further confirmed by a contralateral multiple
TESE, when performed. No significant pre-operative predictors of sperm retrieval, including patients’ age, previous
negative TESE or serological markers (LH, FSH, inhibin B), were observed at univariate or multivariate analysis.
Micro-TESE (step 2) did not improve sperm retrieval as compared to single TESE biopsy on the same testicle
(step 1) or multiple contralateral TESE (step 3).
Conclusions: Stepwise micro-TESE could represent an optimal approach for sperm retrieval in NOA men. In
our view, it should be offered to NOA patients in order to gradually increase surgical invasiveness, when
necessary. Stepwise micro-TESE might also reduce the costs, time and efforts involved in surgery
Testicular histopathology, semen analysis and FSH, predictive value of sperm retrieval: supportive counseling in case of reoperation after testicular sperm extraction (TESE)
Background: To provide indicators for the likelihood of sperm retrieval in patients undergoing testicular sperm extraction is a major issue in the management of male infertility by TESE. The aim of our study was to determine the impact of different parameters, including testicular histopathology, on sperm retrieval in case of reoperation in patients undergoing testicular sperm extraction. Methods: We retrospectively analyzed 486 patients who underwent sperm extraction for intracytoplasmic sperm injection and testicular biopsy. Histology was classified into: normal spermatogenesis; hypospermatogenesis (reduction in the number of normal spermatogenetic cells); maturation arrest (absence of the later stages of spermatogenesis); and Sertoli cell only (absence of germ cells). Semen analysis and serum FSH, LH and testosterone were measured. Results: Four hundred thirty patients had non obstructive azoospermia, 53 severe oligozoospermia and 3 necrozoospermia. There were 307 (63%) successful sperm retrieval. Higher testicular volume, lower levels of FSH, and better histological features were predictive for sperm retrieval. The same parameters and younger age were predictive factors for shorter time for sperm recovery. After multivariable analysis, younger age, better semen parameters, better histological features and lower values of FSH remained predictive for shorter time for sperm retrieval while better semen and histology remained predictive factors for successful sperm retrieval. The predictive capacity of a score obtained by summing the points assigned for selected predictors (1 point for Sertoli cell only, 0.33 points for azoospermia, 0.004 points for each FSH mIU/ml) gave an area under the ROC curve of 0.843. Conclusions: This model can help the practitioner with counseling infertile men by reliably predicting the chance of obtaining spermatozoa with testicular sperm extraction when a repeat attempt is planne
Unbalanced Holographic Superconductors and Spintronics
We present a minimal holographic model for s-wave superconductivity with
unbalanced Fermi mixtures, in 2+1 dimensions at strong coupling. The breaking
of a U(1)_A "charge" symmetry is driven by a non-trivial profile for a charged
scalar field in a charged asymptotically AdS_4 black hole. The chemical
potential imbalance is implemented by turning on the temporal component of a
U(1)_B "spin" field under which the scalar field is uncharged. We study the
phase diagram of the model and comment on the eventual (non) occurrence of
LOFF-like inhomogeneous superconducting phases. Moreover, we study "charge" and
"spin" transport, implementing a holographic realization (and a generalization
thereof to superconducting setups) of Mott's two-current model which provides
the theoretical basis of modern spintronics. Finally we comment on possible
string or M-theory embeddings of our model and its higher dimensional
generalizations, within consistent Kaluza-Klein truncations and brane-anti
brane setups.Comment: 45 pages, 15 figures; v2: two paragraphs below eq. (3.1) slightly
modified, figure 5 (left) replaced, references added; v3: typos corrected,
comments added, figure 12 replace
Acute WNT signalling activation perturbs differentiation within the adult stomach and rapidly leads to tumour formation
A role for WNT signalling in gastric carcinogenesis has been suggested due to two major observations. First, patients with germline mutations in adenomatous polyposis coli (APC) are susceptible to stomach polyps and second, in gastric cancer, WNT activation confers a poor prognosis. However, the functional significance of deregulated WNT signalling in gastric homoeostasis and cancer is still unclear. In this study we have addressed this by investigating the immediate effects of WNT signalling activation within the stomach epithelium. We have specifically activated the WNT signalling pathway within the mouse adult gastric epithelium via deletion of either glycogen synthase kinase 3 (GSK3) or APC or via expression of a constitutively active β-catenin protein. WNT pathway deregulation dramatically affects stomach homoeostasis at very short latencies. In the corpus, there is rapid loss of parietal cells with fundic gland polyp (FGP) formation and adenomatous change, which are similar to those observed in familial adenomatous polyposis. In the antrum, adenomas occur from 4 days post-WNT activation. Taken together, these data show a pivotal role for WNT signalling in gastric homoeostasis, FGP formation and adenomagenesis. Loss of the parietal cell population and corresponding FGP formation, an early event in gastric carcinogenesis, as well as antral adenoma formation are immediate effects of nuclear β-catenin translocation and WNT target gene expression. Furthermore, our inducible murine model will permit a better understanding of the molecular changes required to drive tumourigenesis in the stomach
A comprehensive 1000 Genomes-based genome-wide association meta-analysis of coronary artery disease
Existing knowledge of genetic variants affecting risk of coronary artery disease (CAD) is largely based on genome-wide association studies (GWAS) analysis of common SNPs. Leveraging phased haplotypes from the 1000 Genomes Project, we report a GWAS meta-analysis of 185 thousand CAD cases and controls, interrogating 6.7 million common (MAF>0.05) as well as 2.7 million low frequency (0.005<MAF<0.05) variants. In addition to confirmation of most known CAD loci, we identified 10 novel loci, eight additive and two recessive, that contain candidate genes that newly implicate biological processes in vessel walls. We observed intra-locus allelic heterogeneity but little evidence of low frequency variants with larger effects and no evidence of synthetic association. Our analysis provides a comprehensive survey of the fine genetic architecture of CAD showing that genetic susceptibility to this common disease is largely determined by common SNPs of small effect siz
Evidence for the h_b(1P) meson in the decay Upsilon(3S) --> pi0 h_b(1P)
Using a sample of 122 million Upsilon(3S) events recorded with the BaBar
detector at the PEP-II asymmetric-energy e+e- collider at SLAC, we search for
the spin-singlet partner of the P-wave chi_{bJ}(1P) states in the
sequential decay Upsilon(3S) --> pi0 h_b(1P), h_b(1P) --> gamma eta_b(1S). We
observe an excess of events above background in the distribution of the recoil
mass against the pi0 at mass 9902 +/- 4(stat.) +/- 2(syst.) MeV/c^2. The width
of the observed signal is consistent with experimental resolution, and its
significance is 3.1sigma, including systematic uncertainties. We obtain the
value (4.3 +/- 1.1(stat.) +/- 0.9(syst.)) x 10^{-4} for the product branching
fraction BF(Upsilon(3S)-->pi0 h_b) x BF(h_b-->gamma eta_b).Comment: 8 pages, 4 postscript figures, submitted to Phys. Rev. D (Rapid
Communications
Performance of the CMS Cathode Strip Chambers with Cosmic Rays
The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device
in the CMS endcaps. Their performance has been evaluated using data taken
during a cosmic ray run in fall 2008. Measured noise levels are low, with the
number of noisy channels well below 1%. Coordinate resolution was measured for
all types of chambers, and fall in the range 47 microns to 243 microns. The
efficiencies for local charged track triggers, for hit and for segments
reconstruction were measured, and are above 99%. The timing resolution per
layer is approximately 5 ns
The common good and government in Jacques Maritain
No cabe duda que Maritain ha tenido una influencia considerable en las ideas políticas contemporáneas, en especial en la denominada social democracia. Es por esto que conviene revisar algunas de sus principales teorías respecto a las formas de gobierno y el bien común. Tratar las formas de gobierno y el bien común en Maritain lleva inevitablemente a tener que considerar aspectos metafísicos y antropológicos, en tanto, en el autor son estos aspectos los que de forma posterior determinan o por lo menos influyen de forma considerable en su teoría política.
Como hemos mencionado Maritain concede una importancia significativa a el aspecto antropológico y metafísico, en los relativo al primero, este se hace manifiesto en la noción de persona concebida como un todo, como una realidad sustancial, mientras que el aspecto metafísico puede verse en la idea de Dios como el Bien Común Supremo.There is no doubt that Maritain has had a considerable influence on contemporary political ideas, especially on the so-called social democracy. This is why it is convenient to review some of his main theories regarding the forms of government and the common good. To deal with the forms of government and the common good in Maritain inevitably leads inevitably to consider metaphysical and anthropological aspects, while in the author it is these aspects that subsequently determine or at least considerably influence his political theory.
As we have mentioned Maritain grants a significant importance to the anthropological and metaphysical aspect, in those relative to the first, this is made manifest in the notion of person conceived as a whole, as a substantial reality, while the metaphysical aspect can be seen in the idea of God as the Supreme Common Good
Reactivity of Metal-Free and Metal-Associated Amyloid-?? with Glycosylated Polyphenols and Their Esterified Derivatives
Both amyloid-?? (A??) and transition metal ions are shown to be involved in the pathogenesis of Alzheimer???s disease (AD), though the importance of their interactions remains unclear. Multifunctional molecules, which can target metal-free and metal-bound A?? and modulate their reactivity (e.g., A?? aggregation), have been developed as chemical tools to investigate their function in AD pathology; however, these compounds generally lack specificity or have undesirable chemical and biological properties, reducing their functionality. We have evaluated whether multiple polyphenolic glycosides and their esterified derivatives can serve as specific, multifunctional probes to better understand AD. The ability of these compounds to interact with metal ions and metal-free/-associated A??, and further control both metal-free and metal-induced A?? aggregation was investigated through gel electrophoresis with Western blotting, transmission electron microscopy, UV-Vis spectroscopy, fluorescence spectroscopy, and NMR spectroscopy. We also examined the cytotoxicity of the compounds and their ability to mitigate the toxicity induced by both metal-free and metal-bound A??. Of the polyphenols investigated, the natural product (Verbascoside) and its esterified derivative (VPP) regulate the aggregation and cytotoxicity of metal-free and/or metal-associated A?? to different extents. Our studies indicate Verbascoside represents a promising structure for further multifunctional tool development against both metal-free A?? and metal-A??.open0
Observation of a J^PC = 1-+ exotic resonance in diffractive dissociation of 190 GeV/c pi- into pi- pi- pi+
The COMPASS experiment at the CERN SPS has studied the diffractive
dissociation of negative pions into the pi- pi- pi+ final state using a 190
GeV/c pion beam hitting a lead target. A partial wave analysis has been
performed on a sample of 420000 events taken at values of the squared
4-momentum transfer t' between 0.1 and 1 GeV^2/c^2. The well-known resonances
a1(1260), a2(1320), and pi2(1670) are clearly observed. In addition, the data
show a significant natural parity exchange production of a resonance with
spin-exotic quantum numbers J^PC = 1-+ at 1.66 GeV/c^2 decaying to rho pi. The
resonant nature of this wave is evident from the mass-dependent phase
differences to the J^PC = 2-+ and 1++ waves. From a mass-dependent fit a
resonance mass of 1660 +- 10+0-64 MeV/c^2 and a width of 269+-21+42-64 MeV/c^2
is deduced.Comment: 7 page, 3 figures; version 2 gives some more details, data unchanged;
version 3 updated authors, text shortened, data unchange
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