The band‐gap energies of the CdS semiconductor are obtained by a photoacoustic spectroscopy (PAS) technique over a range of temperature of thermal annealing (TTA), in which the evolution of the sample structure is characterized by x‐ray diffraction patterns. The PAS experiment gives a set of data for the band‐gap shift in the region of the fundamental absorption edge. With increasing TTA the band‐gap shift increases up to a critical TTA when its slope decreases in a roughly symmetrical way. It is suggested that at this temperature a cubic to hexagonal‐lattice transition occurs.

/pdf/band-gap-shift-in-cds-semiconductor-by-photoacoustic-5dimi2j2ui.pdf

Band‐gap shift in CdS semiconductor by photoacoustic spectroscopy: Evidence of a cubic to hexagonal lattice transition

A quantitative analysis of the electronic deformation (electronic strain) contribution to the photoacoustic signal in semiconductor samples was done. The photoacoustic (PA) effect was investigated as a function of the modulation frequency in a transmission detection configuration. The theoretical model for this configuration was given for the thermal and elastic processes besides the carrier transport characteristic and the relation for electronic elastic deformation was derived by the theory of the elastic thin plate vibrations. Analysis showed that the electronic deformation mechanisms can have an important infleucne on the PA signal in the frequency range typical for gas-microphone detection. The experimental photoacoustic data for Si samples were measured and they exhibited a satisfactory agreement with the theoretical model.

Photoacoustic frequency transmission technique: Electronic deformation mechanism in semiconductors

A gradual alteration in the mechanisms underlying reproduction and fertility characterizes the aging process in human females. These changes culminate in menopause, conventionally defined as a cessation of menstrual cycles that marks the end of reproductive capacity. In fact, a central and defining event in menopause is the discontinuation of ovulation, which is correlated with a number of structural and functional changes in the reproductive axis. Despite several decades of research, a degree of uncertainty remains as to whether nonhuman primates undergo menopause, and whether they are suitable models of human reproductive senescence. We review some of the controversies that have clouded our understanding of reproductive aging in nonhuman primates, including issues of definition, timing, comparability of data from wild versus captive populations, and cross-species comparisons. The existing data support the view that menopause occurs in a number of primate species and is not unique to humans.

https://bioone.org/journals/Biology-of-Reproduction/volume-79/issue-3/biolreprod.108.068536/Menopause-in-Nonhuman-Primates1/10.1095/biolreprod.108.068536.pdf

Menopause in Nonhuman Primates

Concept: Ovaries meeting criteria for polycystic ovary morphology during peak reproductive years may no longer meet the criteria with age.

Objective: Ovarian volume and follicle number decrease with age in women with polycystic ovary syndrome (PCOS), permitting age-dependent criteria for PCOM.

Design and Setting: We conducted longitudinal (7–15 year interval) and cross-sectional studies to examine polycystic ovarian morphology over time at an outpatient clinic and pathology laboratory in a tertiary care hospital.

Patients: Subjects included those with PCOS defined by the National Institutes of Health criteria (n = 11 and 483 for longitudinal and cross-sectional, respectively) and control women with regular menstrual cycles and no hyperandrogenism (n = 15 and 367), age 18–64 yr.

Interventions: Subjects underwent an ovarian ultrasound by a single observer.

Main Outcome Measures: Ovarian volume and follicle number were measured and ultrasound findings confirmed by a pathologist in a subset (n = 9).

Results: Ovarian volume (15.2 ± 7.4 vs. 7.1 ± 3.7 ml; P < 0.01) and follicle number (12.8 ± 3.2 vs. 8.1 ± 3.9; P < 0.05) decreased longitudinally in PCOS and control women (volume 11.6 ± 4.4 vs. 5.4 ± 2.2 ml and follicle number 8.3 ± 1.9 vs. 6.3 ± 1.8; both P < 0.005). Using cross-sectional data, log ovarian volume and follicle number decreased in both groups, but the decrease in log ovarian volume was less pronounced in women with PCOS than in controls (P < 0.01). A combination of age, log ovarian volume, follicle number, and testosterone distinguished PCOS subjects from controls with a receiver operator characteristic curve area of 0.90.

Conclusions: Ovarian volume and follicle number decrease with age in women with PCOS and controls necessitating age-based criteria to define polycystic ovarian morphology. It is possible to use these criteria to distinguish PCOS in women over age 40 yr.

/pdf/criteria-for-polycystic-ovarian-morphology-in-polycystic-2a6qxgq070.pdf

Criteria for Polycystic Ovarian Morphology in Polycystic Ovary Syndrome as a Function of Age

Context: We determined the relationship of metabolic syndrome (MBS) to polycystic ovary syndrome (PCOS). Objective: We tested the hypothesis that parental MBS is related to the PCOS phenotype in their offspring. Design/Setting: We phenotyped for MBS and PCOS in our General Clinical Research Center. Patients: Girls with PCOS, 12–19 yr old (n = 36, including one pair of siblings), and their parents (35 mothers, 19 fathers) were recruited from the Pediatric Endocrinology Clinic. Healthy girls, 12–19 yr old (n = 21), were recruited as a reference population. Interventions: We measured anthropometrics, blood pressure, fasting lipids and androgens, oral glucose tolerance, and ultrasonographically determined polycystic ovary status. Main Outcome Measures: MBS in parents, and PCOS features in mothers, were related to the presence of PCOS features in probands. Results: Fathers had strikingly high prevalence of excess adiposity (94% were obese or overweight) and MBS (79%). Premenopausal mothers more commonly had MB...

/pdf/relationship-of-adolescent-polycystic-ovary-syndrome-to-rhncdeal42.pdf

Relationship of Adolescent Polycystic Ovary Syndrome to Parental Metabolic Syndrome

The photoacoustic signal of two semiconductor samples is investigated as a function of the modulation frequency in a heat-transmission configuration. It is shown that, in the frequency range where the sample is thermally thick, the signal amplitude and phase can single out the different fast and slow nonradiative recombination heat sources responsible for the photoacoustic signal. The characterization of the thermal and the carrier transport properties is discussed and some practical procedures for this purpose are also outlined.

http://repositorio.unicamp.br/jspui/bitstream/REPOSIP/98931/1/2-s2.0-35949008660.pdf

Photoacoustic characterization of semiconductors: Transport properties and thermal diffusivity in GaAs and Si

The photoacoustic signal of a narrow-gap semiconductor and of Si is investigated as a function of the modulation frequency through the use of a heat-transmission configuration. It is shown that in the thermally thick modulation-frequency range the signal amplitude can single out the different heating sources responsible for the photoacoustic signal. It is also shown that from the signal phase data, as a function of the modulation frequency, we can obtain the values of the surface recombination velocity and the nonradiative band-to-band recombination time.

/pdf/photoacoustic-investigation-of-semiconductors-influence-of-3878j2f5ta.pdf

Photoacoustic investigation of semiconductors: Influence of carrier diffusion and recombination in PbTe and Si.

Ovarian volume, age and menopausal status

The influence of ion implantation in the thermal properties of silicon wafers at room temperature is investigated using the photoacoustic technique. It is suggested that the observed decrease of the values of both thermal diffusivity and conductivity, as the implantation dose increases, is due to the amorphization of the implanted layer.

A. Pinto Neto

Papers

Photoacoustic characterization of semiconductors: Transport properties and thermal diffusivity in GaAs and Si

Photoacoustic investigation of semiconductors: Influence of carrier diffusion and recombination in PbTe and Si.

Ovarian volume, age and menopausal status

Amorphization of ion‐implanted layers in silicon using photoacoustic detection

P210 Associated factors to urinary and genital symptoms prevalence in climateric and postmenopausal women