Study of TMDs nanosheets based saturable absorber used for Q-switching and mode lock laser system

Pulse width of pulsed laser determinates their applications. For the long pulse laser with µs or ns pulse width, it can be used for telecommunication, remote sensing and medical surgery. For the ultrashort pulse laser with ps or fs pulse width, it can be used for eye-surgery, precise micro- or even nano-machining on transparent material and novel 3D hologram formation. The saturable absorber (SA) is the crucial optical component that switch the laser operation from CW mode to pulse mode passively. Therefore it attract s great research interests from the laser photonic community. &more..

catena-Poly[[aqua­(pyrazino[2,3-f][1,10]phenanthroline-κ2 N 8,N 9)cobalt(II)]-μ-pyrazine-2,3-dicarboxyl­ato-κ3 N 1 O 2:O 3]

In the title compound, [Co(C6H2N2O4)(C14H8N4)(H2O)]n, the Co atom is bonded to one N,N′-bidentate pyrazino[2,3-f][1,10]phenanthroline (Pyphen) ligand, one N,O-bidentate pyrazine-2,3-dicarboxyl­ate (PZDC) dianion and one water mol­ecule in a distorted octa­hedral mer-CoN3O3 geometry. The CoII atoms are bridged by the PZDC dianions, forming an infinite one-dimensional chain running along the b axis. Adjacent chains pack together through π–π stacking inter­actions [centroid–centroid separations = 3.498 (4) and 3.528 (4) Å], and O—H⋯O and O—H⋯N hydrogen bonds involving the water mol­ecule complete the structure

catena-Poly[[aqua­(dipyrido[3,2-a:2′,3′-c]phenazine-κ2 N 4,N 5)iron(II)]-μ-pyrazine-2,3-dicarboxyl­ato-κ3 N 1,O 2:O 3]

In the title compound, [Fe(C6H2N2O4)(C18H10N4)(H2O)]n, the FeII ion adopts a slightly distorted octahedral mer-FeN3O3 geometry, arising from one N,N′-bidentate dipyrido[3,2-a:2′,3′-c]phenazine ligand, one N,O-chelating pyrazine-2,3-dicarboxyl­ate dianion and one water mol­ecule. An O-bonded symmetry-related dianion completes the coordination of the metal. The bridging dianion results in a one-dimensional polymeric chain. Aromatic π–π stacking inter­actions between ligands [centroid–centroid separations = 3.528 (2) and 3.741 (2) Å] and O—H⋯O and O—H⋯N hydrogen bonds link the chains together, leading to a three-dimensional supra­molecular network

A Comparative Simulation Study on the Acoustical Condition of Malaysian Public Secondary Schools’ Classrooms

The establishment of classroom design guidelines is essential in order to provide a conducive setting that promotes optimal teaching and learning outcomes. Most of the learning methods involve hearing and listening which require students to use their auditory skills for speech comprehension. It is vital to design a classroom with optimal acoustic conditions for good speech intelligibility and proper listening quality. However, the importance of classroom acoustics in designing a comfortable learning environment is often neglected. Therefore, this study seeks to i) investigate the acoustic conditions of the existing public-school classrooms and ii) evaluate the effect of several treatment alternatives on acoustic performance through the simulation method. Three (3) classrooms from different public secondary schools were chosen for acoustic evaluations. The existing classrooms’ acoustic parameters, namely reverberation time (RT) and speech transmission index (STI), were initially identified. The impact of acoustic treatments on acoustic performance was further assessed, encompassing variations in ceiling profile configurations and adjustments to surface materials. The findings indicate that the current classrooms' reverberation time (RT) and speech transmission index (STI) did not meet the standard recommendations. Despite the prevailing circumstances, the implementation of acoustic treatments on the ceiling profile and alterations to the surface material yield substantial enhancements in acoustic performance, ultimately leading to the attainment of the required optimal acoustic environment inside the classroom setting

Increased ATP generation in the host cell is required for efficient vaccinia virus production

To search for cellular genes up-regulated by vaccinia virus (VV) infection, differential display-reverse transcription-polymerase chain reaction (ddRT-PCR) assays were used to examine the expression of mRNAs from mock-infected and VV-infected HeLa cells. Two mitochondrial genes for proteins that are part of the electron transport chain that generates ATP, ND4 and CO II, were up-regulated after VV infection. Up-regulation of ND4 level by VV infection was confirmed by Western blotting analysis. Up-regulation of ND4 was reduced by the MAPK inhibitor, apigenin, which has been demonstrated elsewhere to inhibit VV replication. The induction of ND4 expression occurred after viral DNA replication since ara C, an inhibitor of poxviral DNA replication, could block this induction. ATP production was increased in the host cells after VV infection. Moreover, 4.5 μM oligomycin, an inhibitor of ATP production, reduced the ATP level 13 hr after virus infection to that of mock-infected cells and inhibited viral protein expression and virus production, suggesting that increased ATP production is required for efficient VV production. Our results further suggest that induction of ND4 expression is through a Bcl-2 independent pathway

Surgical treatment for thyrotoxic hypokalemic periodic paralysis: case report

Thyrotoxic hypokalemic periodic paralysis (THPP) is a rare, potentially life-threatening endocrine emergency. It is characterized by recurrent muscle weakness and hypokalemia. Because many THPP patients do not have obvious symptoms and signs of hyperthyroidism, misdiagnosis may occur. The published studies revealed that definitive therapy for THPP is control of hyperthyroidism by medical therapy, radioactive iodine or surgery, but the long-term post-operative follow-up result was not observed. We reported two cases of medically refractory THPP with recurrent paralysis of extremities and hypokalemia, and both were combined with thyroid nodules. Both patients were treated with total thyroidectomy; the pathology revealed that one is Graves' disease with thyroid papillary carcinoma, and the other is adenomatous goiter with papillary hyperplasia. No episode of periodic paralysis was noted and laboratory evaluation revealed normal potassium level during the post-operative follow up. Our experience suggests that total thyroidectomy by experienced surgeon is an appropriate and definite treatment for medically refractory THPP, especially in cases combined with thyroid nodules

Enterovirus type 71 2A protease functions as a transcriptional activator in yeast

Enterovirus type 71 (EV71) 2A protease exhibited strong transcriptional activity in yeast cells. The transcriptional activity of 2A protease was independent of its protease activity. EV71 2A protease retained its transcriptional activity after truncation of 40 amino acids at the N-terminus but lost this activity after truncation of 60 amino acids at the N-terminus or deletion of 20 amino acids at the C-terminus. Thus, the acidic domain at the C-terminus of this protein is essential for its transcriptional activity. Indeed, deletion of amino acids from 146 to 149 (EAME) in this acidic domain lost the transcriptional activity of EV71 2A protein though still retained its protease activity. EV71 2A protease was detected both in the cytoplasm and nucleus using confocal microscopy analysis. Coxsackie virus B3 2A protease also exhibited transcriptional activity in yeast cells. As expected, an acidic domain in the C-terminus of Coxsackie virus B3 2A protease was also identified. Truncation of this acidic domain resulted in the loss of transcriptional activity. Interestingly, this acidic region of poliovirus 2A protease is critical for viral RNA replication. The transcriptional activity of the EV71 or Coxsackie virus B3 2A protease should play a role in viral replication and/or pathogenesis

Diffusion Tensor Imaging With Tract-Based Spatial Statistics Reveals White Matter Abnormalities in Patients With Vascular Cognitive Impairment

Purpose: The aim of this study was to evaluate microstructural changes of major white matter (WM) tracts in patients with vascular cognitive impairment (VCI).Method: Diffusion tensor imaging (DTI) data were obtained from 24 subjects with subcortical ischemic vascular disease (SIVD), including 13 subjects with VCI-no dementia (VCIND) and 11 subjects with normal cognition (as a control group). A tract-based spatial statistics approach was performed to investigate WM microstructure in VCIND by integrating multiple indices including fractional anisotropy (FA) and mean diffusivity (MD), which are intra-voxel metrics, and local diffusion homogeneity (LDH), which is an inter-voxel metric.Results: The VCIND group had decreased FA and increased MD values throughout widespread WM areas predominately in the corpus callosum, bilateral internal capsule/corona radiata/posterior thalamic radiation/inferior fronto-occipital fasciculus and right inferior/superior longitudinal fasciculus. There was a slight discrepancy between the distribution of areas with decreased FA and LDH. The FA, MD and LDH values were significantly correlated with cognitive test results. According to a WM tract atlas, 10 major tracts were identified as tracts of interest in which three diffusion metrics simultaneously differed between groups, including bilateral anterior thalamic radiation, forceps minor, right corticospinal tract, bilateral inferior fronto-occipital fasciculus, left inferior and superior longitudinal fasciculus, and bilateral uncinate fasciculus. Receiver operating characteristic (ROC) analysis demonstrated the feasibility of using diffusion metrics along the forceps minor and left anterior thalamic radiation for separating two groups.Conclusion: The results suggest WM microstructural abnormalities contribute to cognitive impairments in SIVD patients. DTI parameters may be potential biomarkers for detecting VCIND from SIVD