72 research outputs found

    Femtosecond RMS timing jitter from 1 GHz InP on-chip mode-locked laser at 1550 nm

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    In this work, we analyze the timing stability of a 1 GHz InP on-chip monolithic mode-locked laser at 1550 nm. 504 fs RMS timing jitter is achieved by a hybrid mode-locking operation

    Effect of Long-Term Nutrient Management Strategies for Pastures on Phosphorus in Surface Runoff and Soil Quality

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    Manure, whether mechanically applied or deposited by grazing animals, has been associated with increased risk of non-point source pollution, especially phosphorus. This is especially true in areas where the industry, especially poultry, has been concentrated in geographical areas that are grain deficient, resulting in a reliance on imported grain for poultry feed. Intensification has resulted in the production of large quantities of poultry manure, within relatively small geographical areas. Surplus litter is typically land applied as a nutrient source or used as an animal feed. The objective of this project was to evaluate the effects of long-term nutrient management strategies using poultry litter as a feed and fertiliser for grazed pasture systems in the Shenandoah Valley of Virginia on soil quality, selected soil chemical characteristics and P losses in surface runoff

    Amplitude noise and RF response analysis of 1 GHz mode-locked pulses from an InP-based laser chip at 1550 nm

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    In this work, we investigate a 1 GHz InP-based hybrid mode-locked laser chip and find an amplitude noise of 0.036 percent. An RF response simulation of its custom-designed mounting PCB is performed providing power transmission between 86 and 92 percent

    RF Analysis of a Sub-GHz InP-Based 1550 nm Monolithic Mode-Locked Laser Chip

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    We report a monolithic sub-GHz repetition rate mode-locked laser with record low pulse-to-pulse RMS timing jitter of 3.65 ps in the passive mode locking regime. We analyse the optical pulse generation in passive and hybrid mode-locking operating regimes, finding narrower RF tone linewidth in the passive regime, attributed to the improved contact structure of the gain sections. The noise performance is also characterized in passive and hybrid regimes, showing RMS integrated timing jitter of approximately 600 fs. For hybrid modelocking, the repetition rate can be varied over a large range from 880 to 990 MHz. We observe broad pulse widths of few hundred picoseconds attributed to the (long folded) waveguide architecture and on-chip multimode interference mirrors. This device subjects a stand-alone, ultra-compact, mode-locking based clock source to realize frequency synthesizers operating over a frequency range from sub-GHz up to approximately 15 GHz

    Circulating and tumor-infiltrating immune checkpoint-xepressing CD8+ Treg/T Cell subsets and their associations with disease-free survival in colorectal cancer patients

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    T cells in the tumor microenvironment (TME) have diverse roles in anti-tumor immunity, including orchestration of immune responses and anti-tumor cytotoxic attack. However, different T cell subsets may have opposing roles in tumor progression, especially in inflammation-related cancers such as colorectal cancer (CRC). In this study, we phenotypically characterized CD3+CD4- (CD8+) T cells in colorectal tumor tissues (TT), normal colon tissues (NT) and in circulation of CRC patients. We investigated the expression levels of key immune checkpoints (ICs) and Treg-related markers in CD8+ T cells. Importantly, we investigated associations between different tumor-infiltrating CD8+ T cell subpopulations and disease-free survival (DFS) in CRC patients. We found that FoxP3 expression and ICs including PD-1, CTLA-4, TIM-3, and LAG-3 were significantly increased in tumor-infiltrating CD8+ T cells compared with NT and peripheral blood. In the TME, we found that TIM-3 expression was significantly increased in patients with early stages and absent lymphovascular invasion (LVI) compared to patients with advanced stages and LVI. Importantly, we report that high levels of certain circulating CD8+ T cell subsets (TIM-3-expressing, FoxP3-Helios-TIM-3+ and FoxP3-Helios+TIM-3+ cells) in CRC patients were associated with better DFS. Moreover, in the TME, we report that elevated levels of CD25+ and TIM-3+ T cells, and FoxP3+Helios-TIM-3+ Tregs were associated with better DFS

    Assessment of Sleep Pattern in Egyptian Elderly Subjects with Vascular Dementia: An Egyptian Study on Elderly Population

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    Background: Sleep is considered to be very important for cognitive function and also cognitive deficits and sleep disorders are influenced by one another. Currently, growing evidence suggests that sleep disturbances is common in vascular dementia (VaD). Study Objectives: The goal of the current study was to assess the disturbance in sleep pattern in patients with vascular dementia(VaD) and compare it to healthy normally cognitive elderly individuals. The study further investigated whether meaningful differences in the Subjective sleep assessment (ESS and PSQI) and sleep measurements (PSG) in VaD patients. Study Design/Method: Overnight PSG recordings and self-reported sleep measures were obtained from 20 healthy elderly subjects and 20 VaD patients at the sleep laboratory. Results: This study showed abnormal subjective sleep quality in all patients and revealed that the most common sleep complaintsamong VaD patients were excessive daytime sleepiness (EDS), sleep disordered breathing (SDB), insomnia and RLS and PLMS and REM behavioral disordered, respectively. Moreover, patients spent more time in stage I sleep, but less time in SWS and REM sleep compared to control populations, with delayed REML and less 1st REML. In addition, increased sleep fragmentation (WASO and SFI) and increased AI and PLMS index were detected in VaD patients. Finally, VaD patients had significantly (p < 0.05) high apnea, hypopnea and RDI score with high average SpO2 desaturation. Conclusions: It is conclude that sleep is significantly (p < 0.05) impaired in patients with VaD at both the objective and subjective levels which may be used as a diagnostic marker of VaD. SBD is a common feature of VaD leading to fragmented sleep, increased nocturnal confusion and excessive daytime sleepiness. Subjective sleep assessment questionnaire by (ESS and PSQI) can be used in VaD patients when objective sleep assessment by PSG recordings is difficult to be done. The PSG study of sleep continuity, sleep architecture and REM sleep may help in the prevention of progression of VaD

    Perspectives of frontline professionals on Palestinian children's experiences of parental and sibling drug abuse in the West Bank and Gaza.

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    The Occupied Territories of Palestine (OtP) consists of the non-contiguous West Bank including East Jerusalem, and the Gaza Strip. Political and economic tensions and its dense populations compounds the impact of drug abuse and addiction in the home. A qualitative study using four focus groups (n=42) was conducted in West Bank and Gaza Strip explored the experiences of professionals working with Palestinian families and children affected by substance use and addiction in the home. Data were analysed using thematic analysis (TA), and four themes emerged. These were ‘The rising and shifting problem of drug use in Palestine’; ‘Psychosocial causal factors of drug use in Palestine’; ‘The consequences for children and families living with drug use’; and ‘Potential solutions to the problem are complex and multi-faceted.’ The study paints a concerning picture of how drug abuse impacts on Palestinian families subjected to multiple pressures, stigmas, risks and harms relating to their situation

    Kinetic non-reversibility of the cracking reactions and its accounting during mathematical modeling of industrial process

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    The paper presents the approach to the catalytic cracking modeling with consideration of the reactions' reversibility/non-reversibility depending on the current concentrations and the cracking temperature. The thermodynamic analysis of the reactions using the quantum-chemical methods allows formulating a hydrocarbons conversion scheme at the thermal equilibrium temperature between the feedstock and the catalyst. The magnitude of the current chemical attraction of reactions is a criterion of thermodynamic non-reversibility of reactions, which is determined at each stage of the calculation. It has been shown that the change in the concentrations of conversion participants and cracking temperature have a significant effect on the catalytic cracking reactions. Thus, the cyclization reactions are non-reversible up to 512.9 °C (A[rij]=6.46 kJ/mol) during the processing of feedstock with saturated hydrocarbons to aromatics ratio is 2.1 and with further temperature increasing the contribution of reverse reactions rises. Also with increasing the saturated hydrocarbons to aromatics ratio from 2.1 to 3.2 in the feedstock, the equilibrium of the reaction shifts to low temperatures from 512.9 to 508.9 °C (A[rij]=6.497 kJ/mol). It is connected with the fact that intensification of the exotermic reactions (alkylation, condensation, coke formation) under certain conditions is possible. It is an important factor in terms of catalyst deactivation and has an effect on the desired product yield

    Characterizing the Role of Cell-Wall β-1,3-Exoglucanase Xog1p in Candida albicans Adhesion by the Human Antimicrobial Peptide LL-37

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    Candida albicans is the major fungal pathogen of humans. Its adhesion to host-cell surfaces is the first critical step during mucosal infection. Antimicrobial peptides play important roles in the first line of mucosal immunity against C. albicans infection. LL-37 is the only member of the human cathelicidin antimicrobial peptide family and is commonly expressed in various tissues, including epithelium. We previously showed that LL-37 significantly reduced C. albicans adhesion to plastic, oral epidermoid OECM-1 cells, and urinary bladders of female BALB/c mice. The inhibitory effect of LL-37 on cell adhesion occurred via the binding of LL-37 to cell-wall carbohydrates. Here we showed that formation of LL-37–cell-wall protein complexes potentially inhibits C. albicans adhesion to polystyrene. Using phage display and ELISA, we identified 10 peptide sequences that could bind LL-37. A BLAST search revealed that four sequences in the major C. albicans cell-wall β-1,3-exoglucanase, Xog1p, were highly similar to the consensus sequence derived from the 10 biopanned peptides. One Xog1p-derived peptide, Xog1p90–115, and recombinant Xog1p associated with LL-37, thereby reversing the inhibitory effect of LL-37 on C. albicans adhesion. LL-37 reduced Xog1p activity and thus interrupted cell-wall remodeling. Moreover, deletion of XOG1 or another β-1,3-exoglucanase-encoding gene EXG2 showed that only when XOG1 was deleted did cellular exoglucanase activity, cell adhesion and LL-37 binding decrease. Antibodies against Xog1p also decreased cell adhesion. These data reveal that Xog1p, originally identified from LL-37 binding, has a role in C. albicans adhesion to polystyrene and, by inference, attach to host cells via direct or indirect manners. Compounds that target Xog1p might find use as drugs that prevent C. albicans infection. Additionally, LL-37 could potentially be used to screen for other cell-wall components involved in fungal cell adhesion
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