Development of Single-Molecule Force and Torque Measurement with Application to Nucleosome Disruption

Single-molecule force spectroscopy is a powerful method in biophysical research. The ability of detecting and manipulating single molecule finds applications in studies from DNA to cell, leads to various mechanism-based results. Among many tools in this field, optical traps is suitable for studies involving nucleic acids and its interaction with protein due to the high temporal and spatial resolution. While most experiments characterize force and displacement, the quest for manipulating and detecting torque and angular motion is increasing due to their significant role in many biological processes. This thesis mainly devotes to the development and application of an optical torque wrench which is capable of simultaneously controlling and measuring force, displacement, torque, and angular displacement of a single bio-molecule. First, angular manipulation of oblate polystyrene particles is demonstrated. Moreover, a new method for fabricating birefringent nanocylinders via nanosphere lithography is presented. Both particles are shown to provide stable angular trapping in a home-built optical torque wrench. We then apply them in measuring a single DNA molecule under force and torque. Mechanical stability of nucleosome under tension and torsion is also studied, followed by a theoretical model to elucidate the importance of torsion in such experiments. Finally, the effect of experimental parameters in a surface-based optical traps on measured kinetics of bio-molecule is detailed

5-Hy­droxy­indan-1-one

In the title compound (5HIN), C9H8O2, is perfectly planar as all atoms, except the H atoms of both CH2 groups, lie on a crystallographic mirror plane. In the crystal, mol­ecules are linked by strong inter­molecular O—H⋯O hydrogen bonds, forming an infinite chain along [100], generating a C(8) motif

A Learning-Based EM Clustering for Circular Data with Unknown Number of Clusters

Clustering is a method for analyzing grouped data. Circular data were well used in various applications, such as wind directions, departure directions of migrating birds or animals, etc. The expectation & maximization (EM) algorithm on mixtures of von Mises distributions is popularly used for clustering circular data. In general, the EM algorithm is sensitive to initials and not robust to outliers in which it is also necessary to give a number of clusters a priori. In this paper, we consider a learning-based schema for EM, and then propose a learning-based EM algorithm on mixtures of von Mises distributions for clustering grouped circular data. The proposed clustering method is without any initial and robust to outliers with automatically finding the number of clusters. Some numerical and real data sets are used to compare the proposed algorithm with existing methods. Experimental results and comparisons actually demonstrate these good aspects of effectiveness and superiority of the proposed learning-based EM algorithm

Factors Related to Intra-Tendinous Morphology of Achilles Tendon in Runners

The purpose of this study was to determine and explore factors (age, sex, anthropometry, running and injury/pain history, tendon gross morphology, neovascularization, ankle range of motion, and ankle plantarflexor muscle endurance) related to intra-tendinous morphological alterations of the Achilles tendon in runners. An intra-tendinous morphological change was defined as collagen fiber disorganization detected by a low peak spatial frequency radius (PSFR) obtained from spatial frequency analysis (SFA) techniques in sonography. Ninety-one runners (53 males and 38 females; 37.9 ± 11.6 years) with 8.8 ± 7.3 years of running experience participated. Height, weight, and waist and hip circumferences were recorded. Participants completed a survey about running and injury/pain history and the Victorian Institute of Sport Assessment-Achilles (VISA-A) survey. Heel raise endurance and knee-to-wall composite dorsiflexion were assessed. Brightness-mode (B-mode) sonographic images were captured longitudinally and transversely on the Achilles tendon bilaterally. Sonographic images were analyzed for gross morphology (i.e., cross-sectional area [CSA]), neovascularization, and intra-tendinous morphology (i.e., PSFR) for each participant. The factors associated with altered intra-tendinous morphology of the Achilles tendon were analyzed using a generalized linear mixed model. Multivariate analyses revealed that male sex was significantly associated with a decreased PSFR. Additionally, male sex and the presence of current Achilles tendon pain were found to be significantly related to decreased PSFR using a univariate analysis. Our findings suggested that male sex and presence of current Achilles tendon pain were related to intra-tendinous morphological alterations in the Achilles tendon of runners

Sonographic Detection of Pseudoaneurysm in Vascular Injury in Emergency Department

A 31-year-old man suffered from a stab wound to the lower extremity. The patient had a hard sign of a vascular injury (a diminished distal pulse) and therefore probably should have undergone operative repair, but refused. One week later, he returned to our emergency department with a painful right thigh swelling. Bedside sonography was used to detect a pseudoaneurysm. Emergency sonography is a fast, non-invasive, and rapid decision-making approach in emergency practice

Safety and Efficacy of Tien-Hsien Liquid Practical in Patients with Refractory Metastatic Breast Cancer: A Randomized, Double-Blind, Placebo-Controlled, Parallel-Group, Phase IIa Trial

To evaluate the safety and efficacy of Tien-Hsien Liquid Practical (THL-P), a Chinese herbal mixture, in patients with refractory metastatic breast cancer, we performed a randomized, double-blind, placebo-controlled, parallel-group, phase IIa pilot trial. Patients were randomly assigned to either receive THL-P or matching placebo and followed up every 4 weeks for 24 weeks. The primary endpoint was changes in the global health status/quality of life (GHS/QOL) scale. The secondary endpoints were changes in functional and symptom scales, immunomodulating effects, and adverse events. Sixty-three patients were enrolled between June 2009 and June 2011. The intent-to-treat population included 28 patients in the THL-P group and 11 patients in the placebo group. Compared to the placebo group, the THL-P group had significant improvement from baseline to last visit in GHS/QOL (41.7 versus −33.3; P < 0.05), CD3, CD4/CD8, CD19, CD16+56 positive cells (P < 0.05), and higher levels of physical, role, emotional, and cognitive functioning, as well as decreased fatigue and systemic side effects. Treatment-related adverse events were mild constipation and localized itching, and no serious adverse events were reported. THL-P appears to be a safe alternative adjuvant treatment for patients with refractory metastatic breast cancer, as it effectively improves QOL and palliates cancer-related symptoms

School Organizational Innovative Indicators For Technical Universities And Institutes

This study aimed to construct the organizational innovation indicators of technical universities and institutes. This study held a group discussion and expert focus meeting and afterward, this study generalized seven facets of school organizational innovation: leadership innovation, administration innovation, student guidance and activity innovation, curriculum and instruction innovation, teacher professional development innovation, resource application innovation, and campus construction innovation. Then 25 criteria and 83 indices were developed

Peritoneal Dialysis in Infants and Children After Open Heart Surgery

BackgroundInfants and children who undergo surgical repair of complex congenital heart diseases are prone to developing renal dysfunction. The purpose of this study was to investigate the risk factors associated with prolonged peritoneal dialysis (PD) and the mortality of pediatric patients with acute renal failure (ARF) after open heart surgery.MethodsFrom June 1999 to May 2007, a total of 542 children underwent open heart surgery for congenital heart disease. Fifteen (2.8%) experienced ARF and seven (1.3%) required PD. The clinical and laboratory variables were compared between the survivor and non-survivor groups of ARF patients that needed PD.ResultsThe non-survivors (n = 3, 43%) had a longer cardiopulmonary bypass time (154 ± 21 vs. 111 ± 8 minutes, p = 0.012) and longer aorta clamping time (92 ± 40 vs. 66 ± 15 minutes, p = 0.010) than the survivors (n = 4, 57%). Before the PD, the pH and base excess of the arterial blood gas analysis in the survivors was much higher than that non-survivors (7.30 ± 0.04 vs. 7.16 ± 0.10, p = 0.039; −5.15 ± 3.13 vs. −12.07 ± 2.9 mmol/L, p = 0.031). Furthermore, the survivors had a shorter interval between the onset of ARF and the day the PD was begun (1.2 ± 0.4 vs. 4.3 ± 1.2 days, p = 0.001), and shorter duration of PD (6.6 ± 2.7 vs. 13.0 ± 3.5 days, p= 0.036) than non-survivors.ConclusionEarly intervention with PD is a safe and effective method for managing patients with ARF after open heart surgery. The cardiopulmonary bypass and aortic clamping duration, time of initiating PD, duration of the PD, sepsis, and relative complications may predict the prognosis of these patients