Different regimes of Forster energy transfer between an epitaxial quantum well and a proximal monolayer of semiconductor nanocrystals

We calculate the rate of non-radiative, Forster-type energy transfer (ET) from an excited epitaxial quantum well (QW) to a proximal monolayer of semiconductor nanocrystal quantum dots (QDs). Different electron-hole configurations in the QW are considered as a function of temperature and excited electron-hole density. A comparison of the theoretically determined ET rate and QW radiative recombination rate shows that, depending on the specific conditions, the ET rate is comparable to or even greater than the radiative recombination rate. Such efficient Forster ET is promising for the implementation of ET-pumped, nanocrystal QD-based light emitting devices.Comment: 14 pages, 4 figure

Wound fluid ceftriaxone concentrations after local application with calcium sulphate as carrier material in the treatment of orthopaedic device-associated hip infections.

There is a considerable challenge in treating bone infections and orthopaedic device-associated infection (ODAI), partly due to impaired penetration of systemically administrated antibiotics at the site of infection. This may be circumvented by local drug administration. Knowledge of the release kinetics from any carrier material is essential for proper application. Ceftriaxone shows a particular constant release from calcium sulphate (CaSO <sub>4</sub> ) in vitro, and is particularly effective against streptococci and a large portion of Gram-negative bacteria. We present the clinical release kinetics of ceftriaxone-loaded CaSO <sub>4</sub> applied locally to treat ODAI. A total of 30 operations with ceftriaxone-loaded CaSO <sub>4</sub> had been performed in 28 patients. Ceftriaxone was applied as a single local antibiotic in 21 operations and combined with vancomycin in eight operations, and in an additional operation with vancomycin and amphotericin B. Sampling of wound fluid was performed from drains or aspirations. Ceftriaxone concentrations were measured by liquid chromatography with tandem mass spectrometry (LC-MS/MS). A total of 37 wound fluid concentrations from 16 operations performed in 14 patients were collected. The ceftriaxone concentrations remained approximately within a range of 100 to 200 mg/l up to three weeks. The median concentration was 108.9 mg/l (interquartile range 98.8 to 142.5) within the first ten days. No systemic adverse reactions were observed. Our study highlights new clinical data of locally administered ceftriaxone with CaSO <sub>4</sub> as carrier material. The near-constant release of ceftriaxone from CaSO <sub>4</sub> observed in vitro could be confirmed in vivo. The concentrations remained below known local toxicity thresholds.Cite this article: Bone Joint Res 2022;11(11):835-842

A Patient with Proopiomelanocortin Deficiency: An Increasingly Important Diagnosis to Make

Proopiomelanocortin (POMC) deficiency is a rare monogenic disorder with early-onset obesity. Investigation of this entity have increased our insight into the important role of the leptin-melanocortin pathway in energy balance. Here, we present a patient with POMC deficiency due to a homozygous c.206delC mutation in the POMC gene. We discuss the pathogenesis of this condition with emphasis on the crosstalk between hypothalamic and peripheral signals in the development of obesity and the POMC-melanocortin 4 receptors system as a target for therapeutic intervention

Long-term outcome of partial P450 side-chain cleavage enzyme deficiency in three brothers: the importance of early diagnosis.

Objective: CYP11A1 mutations cause P450 side-chain cleavage (scc) deficiency, a rare form of congenital adrenal hyperplasia with a wide clinical spectrum. We detail the phenotype and evolution in a male sibship identified by HaloPlex targeted capture array. Family study: The youngest of three brothers from a non-consanguineous Scottish family presented with hyperpigmentation at 3.7 years. Investigation showed grossly impaired glucocorticoid function with ACTH elevation, moderately impaired mineralocorticoid function, and normal external genitalia. The older brothers were found to be pigmented also, with glucocorticoid impairment but normal electrolytes. Linkage studies in 2002 showed that all three brothers had inherited the same critical regions of the maternal X chromosome suggesting an X-linked disorder, but analysis of NR0B1 (DAX-1, adrenal hypoplasia) and ABCD1 (adrenoleukodystrophy) were negative. In 2016, next-generation sequencing revealed compound heterozygosity for the rs6161 variant in CYP11A1 (c.940G>A, p.Glu314Lys), together with a severely disruptive frameshift mutation (c.790_802del, K264Lfs*5). The brothers were stable on hydrocortisone and fludrocortisone replacement, testicular volumes (15-20 mL), and serum testosterone levels (24.7, 33.3, and 27.2 nmol/L) were normal, but FSH (41.2 µ/L) was elevated in the proband. The latter had undergone left orchidectomy for suspected malignancy at the age of 25 years and was attending a fertility clinic for oligospermia. Initial histology was reported as showing nodular Leydig cell hyperplasia. However, histological review using CD56 staining confirmed testicular adrenal rest cell tumour (TART). Conclusion: This kinship with partial P450scc deficiency demonstrates the importance of precise diagnosis in primary adrenal insufficiency to ensure appropriate counselling and management, particularly of TART

Analysis of the Temporal Organization of Sleep Spindles in the Human Sleep EEG Using a Phenomenological Modeling Approach

The sleep electroencephalogram (EEG) is characterized by typical oscillatory patterns such as sleep spindles and slow waves. Recently, we proposed a method to detect and analyze these patterns using linear autoregressive models for short (≈ 1 s) data segments. We analyzed the temporal organization of sleep spindles and discuss to what extent the observed interevent intervals correspond to properties of stationary stochastic processes and whether additional slow processes, such as slow oscillations, have to be assumed. We have found evidence for such an additional slow process, most pronounced in sleep stage 2

Implications of the Cosmic Background Imager Polarization Data

We present new measurements of the power spectra of the E-mode of CMB polarization, the temperature T, the cross-correlation of E and T, and upper limits on the B-mode from 2.5 years of dedicated Cosmic Background Imager (CBI) observations. Both raw maps and optimal signal images in the uv-plane and real space show strong detections of the E-mode (11.7 sigma for the EE power spectrum overall) and no detection of the B-mode. The power spectra are used to constrain parameters of the flat tilted adiabatic Lambda-CDM models: those determined from EE and TE bandpowers agree with those from TT, a powerful consistency check. There is little tolerance for shifting polarization peaks from the TT-forecast locations, as measured by the angular sound crossing scale theta = 100 ell_s = 1.03 +/- 0.02 from EE and TE cf. 1.044 +/- 0.005 with the TT data included. The scope for extra out-of-phase peaks from subdominant isocurvature modes is also curtailed. The EE and TE measurements of CBI, DASI and BOOMERANG are mutually consistent, and, taken together rather than singly, give enhanced leverage for these tests.Comment: 15 pages, 9 figures, submitted to ApJ -- Accepted version. The fine-bin spectrum, covariance matrix, and window functions are now available on the web (suitable for use in COSMOMC) at: http://www.astro.caltech.edu/~tjp/CBI/data2006/index.html The pipeline in the previous version inadvertently omitted one antenna, so the new spectrum contains ~15% more data. We emphasize that previous results were in no way biased, and that the (small) changes to the spectrum solely reflect the inclusion of the additional data. Numbers and figures in the paper have been updated correspondingly. All maps now have color bar

Next generation sequencing reveals novel genetic variants (SRY, DMRT1, NR5A1, DHH, DHX37) in adults with 46,XY DSD

Context: The genetic basis of human sex development is slowly being elucidated and more than 40 different genetic causes of differences (or disorders) of sex development (DSD) have now been reported. However, reaching a specific diagnosis using traditional approaches can be difficult, especially in adults where limited biochemical data may be available. / Objective: We used a targeted next-generation sequencing approach to analyze known and candidate genes for DSD in individuals with no specific molecular diagnosis. / Partcipants and Design: We studied 52 adult 46,XY women attending a single-center adult service, who were part of a larger cohort of 400 individuals. Classic conditions such as17β-hydroxysteroid dehydrogenase deficiency type 3, 5α-reductase deficiency type 2 and androgen insensitivity syndrome were excluded. The study cohort had broad working diagnoses of complete gonadal dysgenesis (CGD) (n=27) and partially-virilised 46,XY DSD (pvDSD) (n=25), a group that included partial gonadal dysgenesis (PGD) and those with a broad ”partial androgen insensitivity syndrome” label. Targetted sequencing of 168 genes was undertaken. / Results: Overall a likely genetic cause was found in 16/52 (30.8%) individuals (22.2% CGD; 40.0% pvDSD). Pathogenic variants were found in SRY (n=3), DMRT1 (n=1), NR5A1/SF-1 (n=1) and DHH (n=1) in the CGD group, and in NR5A1 (n=5), DHH (n=1) and DHX37 (n=4) in the pvDSD group. / Conclusions: Reaching a specific diagnosis can have clinical implications and provides insight into the role of these proteins in sex development. Next-generation sequencing approaches are invaluable, especially in adult populations or where diagnostic biochemistry is not possible