The acceleration of electrons to approximately 0.8 GeV has been observed in a self-injecting laser wakefield accelerator driven at a plasma density of 5.5x10(18) cm(-3) by a 10 J, 55 fs, 800 nm laser ...pulse in the blowout regime. The laser pulse is found to be self-guided for 1 cm (>10zR), by measurement of a single filament containing >30% of the initial laser energy at this distance. Three-dimensional particle in cell simulations show that the intensity within the guided filament is amplified beyond its initial focused value to a normalized vector potential of a0>6, thus driving a highly nonlinear plasma wave.
There are seven conserved CTCF binding domains in the herpes simplex virus 1 (HSV-1) genome. These binding sites individually flank the latency-associated transcript (LAT) and the immediate early ...(IE) gene regions, suggesting that CTCF insulators differentially control transcriptional domains in HSV-1 latency. In this work, we show that two CTCF binding motifs in HSV-1 display enhancer blocking in a cell-type-specific manner. We found that CTCF binding to the latent HSV-1 genome was LAT dependent and that the quantity of bound CTCF was site specific. Following reactivation, CTCF eviction was dynamic, suggesting that each CTCF site was independently regulated. We explored whether CTCF sites recruit the polycomb-repressive complex 2 (PRC2) to establish repressive domains through a CTCF-Suz12 interaction and found that Suz12 colocalized to the CTCF insulators flanking the ICP0 and ICP4 regions and, conversely, was removed at early times postreactivation. Collectively, these data support the idea that CTCF sites in HSV-1 are independently regulated and may contribute to lytic-latent HSV-1 control in a site-specific manner.
The role of chromatin insulators in DNA viruses is an area of interest. It has been shown in several beta- and gammaherpesviruses that insulators likely control the lytic transcriptional profile through protein recruitment and through the formation of three-dimensional (3D) chromatin loops. The ability of insulators to regulate alphaherpesviruses has been understudied to date. The alphaherpesvirus HSV-1 has seven conserved insulator binding motifs that flank regions of the genome known to contribute to the establishment of latency. Our work presented here contributes to the understanding of how insulators control transcription of HSV-1.
We compare for the first time the influence of different Yb:YAG gain media on the performance of a large-area, high average-power laser system with an output energy of up to 6 J. Monocrystalline ...slabs grown by a new technique without central growth defect are compared with ceramics. Small signal gain, maximum output energy and thermal lensing are compared for ceramic slabs with co-sintered amplified spontaneous emission (ASE) absorber cladding, monocrystalline slab with and without optically bonded ASE absorber cladding, and surface structured monocrystalline slabs. We show that these large monocrystals with optically bonded absorber cladding have similar performance to cladded ceramics, so far the only material for high-energy Yb:YAG lasers.
Glaucoma, a leading cause of irreversible blindness, affects more than 64 million people worldwide and is expected to grow in number due to the aging global population and enhanced methods of ...detection. Although topical therapies are often effective when used as prescribed, the drawbacks of current medical management methods include poor patient adherence, local and systemic side effects, and in some cases, limited therapeutic efficacy. Novel ocular drug delivery platforms promise to deliver differentiated drug formulations with targeted delivery leveraging patient-independent administration. Several platforms are in various stages of development with promising pre-clinical and clinical data. The Bimatoprost Sustained Release (SR) intracameral implant was approved in the United States in March of 2020, making it the first long-term injectable therapy available for the treatment of glaucoma. This review aims to provide an update on novel sustained release drug delivery systems that are available today as well as those that might be commercialized in coming years.
To compare intraocular pressure (IOP) readings obtained with Perkins tonometry, iCare Home, iCare 200, and Tonopen to IOP readings obtained with the manometer of a perfusion system to assess the ...accuracy and reproducibility of each method of tonometry at set pressures.
The IOP of human cadaveric eyes (
=2) was measured using a manometer inserted into the eye through the optic nerve. IOP measurements were obtained using a Perkins tonometer, iCare Home, iCare 200, and Tonopen. These measurements were compared to set point IOP measurements of a manometer to determine accuracy and reproducibility of each device.
Mean IOP readings obtained with the Perkins tonometer compared to manometer readings demonstrated a difference of -1.0±5.0 mm Hg (
=0.45), indicating a lower reading on average than manometery although not significant. Mean IOP difference between iCare 200 and manometer was 5.3±2.2 mm Hg (
<0.0001). Mean difference in IOP between iCare Home and manometer was 3.5±2.4 mm Hg (
=0.0004). Mean IOP difference compared to manometer was 4.6±4.0 mm Hg for the Tonopen (
<0.0001). IOP measurements obtained with the Perkins tonometer demonstrated a standard deviation of 5.0 mm Hg while the Tonopen measurements demonstrated a 4.0 mm Hg standard deviation. In comparison, iCare 200 and iCare Home demonstrated 2.2 and 2.4 mm Hg standard deviation, respectively.
Applanation tonometry produces more accurate IOP readings than rebound tonometry or Tonopen, however it demonstrates greater variability than the other forms of tonometry. Rebound tonometry is more reproducible but tends to over-estimate IOP.
We present a numerical model of a pulsed, diode-pumped Yb:YAG laser amplifier for the generation of high energy ns-pulses. This model is used to explore how optical-to-optical efficiency depends on ...factors such as pump duration, pump spectrum, pump intensity, doping concentration, and operating temperature. We put special emphasis on finding ways to achieve high efficiency within the practical limitations imposed by real-world laser systems, such as limited pump brightness and limited damage fluence. We show that a particularly advantageous way of improving efficiency within those constraints is operation at cryogenic temperature. Based on the numerical findings we present a concept for a scalable amplifier based on an end-pumped, cryogenic, gas-cooled multi-slab architecture.
Laser-plasma wakefield-based electron accelerators are expected to deliver ultrashort electron bunches with unprecedented peak currents. However, their actual pulse duration has never been directly ...measured in a single-shot experiment. We present measurements of the ultrashort duration of such electron bunches by means of THz time-domain interferometry. With data obtained using a 0.5 J, 45 fs, 800 nm laser and a ZnTe-based electro-optical setup, we demonstrate the duration of laser-accelerated, quasimonoenergetic electron bunches best fit of 32 fs (FWHM) with a 90% upper confidence level of 38 fs to be shorter than the drive laser pulse, but similar to the plasma period.
HURTADO D.A., SABBATH E.L., ERTEL K.A., BUXTON O.M. & BERKMAN L.F. (2012) Racial disparities in job strain among American and immigrant long‐term care workers. International Nursing Review59, 237–244
...Background: Nursing homes are occupational settings, with an increasing minority and immigrant workforce where several psychosocial stressors intersect.
Aim: This study aimed to examine racial/ethnic differences in job strain between Black (n = 127) and White (n = 110) immigrant and American direct‐care workers at nursing homes (total n = 237).
Methods: Cross‐sectional study with data collected at four nursing homes in Massachusetts during 2006‐2007. We contrasted Black and White workers within higher‐skilled occupations such as registered nurses or licensed practical nurses (n = 82) and lower‐skilled staff such as certified nursing assistants (CNAs, n = 155).
Results: Almost all Black workers (96%) were immigrants. After adjusting for demographic and occupational characteristics, Black employees were more likely to report job strain, compared with Whites relative risk (RR): 2.9, 95% confidence interval (CI) 1.3 to 6.6. Analyses stratified by occupation showed that Black CNAs were more likely to report job strain, compared with White CNAs (RR: 3.1, 95% CI: 1.0 to 9.4). Black workers were also more likely to report low control (RR: 2.1, 95% CI: 1.1 to 4.0). Additionally, Black workers earned $2.58 less per hour and worked 7.1 more hours per week on average, controlling for potential confounders.
Conclusion: Black immigrant workers were 2.9 times more likely to report job strain than White workers, with greater differences among CNAs. These findings may reflect differential organizational or individual characteristics but also interpersonal or institutional racial/ethnic discrimination. Further research should consider the role of race/ethnicity in shaping patterns of occupational stress.
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