Direct Visualization of 3-Dimensional Force and Energy Map of a Single Molecular Switch

Mechanical properties of molecules adsorbed on materials surfaces are increasingly vital for the applications of molecular thin films. Here, we conduct a fundamental research to induce conformational change mechanically on a single molecule and quantify the driving force needed for such molecular shape switch via a low temperature (~ 5K) Scanning Tunneling Microscope (STM) and Qplus Atomic Force Microscope (Q+AFM). Our measurement maps a three-dimensional landscape for mechanical potential and force at single molecule level with high spatial resolution in all three dimensions of a few angstrom (10-10 m). Molecule TBrPP-Co (a cobalt porphyrin) deposited on an atomically clean gold substrate typically has two of its pentagon rings tilted upward and the other two downward. An atomically sharp tip of the STM/Q+AFM, which vibrates with a high frequency (~ 30kHz), is employed to scan the molecule at different heights with 0.1Å increment and meanwhile record tip-molecule interaction strength in the form of tip frequency change. When tip approaches to the threshold distance to the molecule, mechanical force become large enough and cause pentagon rings flip their direction. Due to the sensitive nature of tip-molecule interaction, the rings flipping can be directly visualized by STM, as rings tilting upward exhibit two bright protrusions in contrast to rings downward in image. By processing frequency change, we obtain a three-dimensional mechanical potential and force map for a single molecule with the resolution of angstrom level in all three dimensions. Our preliminary results indicate that an energy barrier of ~400meV needs to be overcome for rings flipping of TBrPP-Co.https://digitalcommons.odu.edu/gradposters2021_sciences/1015/thumbnail.jp

Prostate carcinogenesis predictor

A method of detecting prostate tumorigenesis in a subject, the method including the steps of (a) obtaining a sample from the prostate of the human subject, (b) detecting quantitatively or semi-quantitatively in the sample a level of expression for PKC-ι and (c) comparing the expression level in (b) to a level of expression in a normal control, wherein overexpression of PKC-ι, with respect to the control, indicates the presence of prostate cancer in the subject. The present invention is based upon the discovery that PKC-ι levels are elevated during prostate tumorigenesis. Furthermore, the proliferation rate of the tumor correlates with the level of PKC-ι. The invention also provides methods of treating prostate cancer by administering to the subject a compound that inhibits the expression of PKC-ι. The compound can be a small interfering RNA (siRNA) molecule

Prostate carcinogenesis predictor

A method of detecting prostate tumorigenesis in a subject, the method including the steps of (a) obtaining a sample from the prostate of the human subject, (b) detecting quantitatively or semi-quantitatively in the sample a level of expression for PKC-ι and (c) comparing the expression level in (b) to a level of expression in a normal control, wherein overexpression of PKC-ι, with respect to the control, indicates the presence of prostate cancer in the subject. The present invention is based upon the discovery that PKC-ι levels are elevated during prostate tumorigenesis. Furthermore, the proliferation rate of the tumor correlates with the level of PKC-ι. The invention also provides methods of treating prostate cancer by administering to the subject a compound that inhibits the expression of PKC-ι. The compound can be a small interfering RNA (siRNA) molecule

Prostate carcinogenesis predictor

A method of detecting prostate tumorigenesis in a subject, the method including the steps of (a) obtaining a sample from the prostate of the human subject, (b) detecting quantitatively or semi-quantitatively in the sample a level of expression for PKC-ι and (c) comparing the expression level in (b) to a level of expression in a normal control, wherein overexpression of PKC-ι, with respect to the control, indicates the presence of prostate cancer in the subject. The present invention is based upon the discovery that PKC-ι levels are elevated during prostate tumorigenesis. Furthermore, the proliferation rate of the tumor correlates with the level of PKC-ι. The invention also provides methods of treating prostate cancer by administering to the subject a compound that inhibits the expression of PKC-ι. The compound can be a small interfering RNA (siRNA) molecule

Current practice in the management of ocular toxoplasmosis

Background Ocular toxoplasmosis is common across all regions of the world. Understanding of the epidemiology and approach to diagnosis and treatment have evolved recently. In November 2020, an international group of uveitis-specialised ophthalmologists formed the International Ocular Toxoplasmosis Study Group to define current practice. Methods 192 Study Group members from 48 countries completed a 36-item survey on clinical features, use of investigations, indications for treatment, systemic and intravitreal treatment with antiparasitic drugs and corticosteroids, and approach to follow-up and preventive therapy. Results For 77.1% of members, unilateral retinochoroiditis adjacent to a pigmented scar accounted for over 60% of presentations, but diverse atypical presentations were also reported. Common complications included persistent vitreous opacities, epiretinal membrane, cataract, and ocular hypertension or glaucoma. Most members used clinical examination with (56.8%) or without (35.9%) serology to diagnose typical disease but relied on intraocular fluid testing-usually PCR-in atypical cases (68.8%). 66.1% of members treated all non-pregnant patients, while 33.9% treated selected patients. Oral trimethoprim-sulfamethoxazole was first-line therapy for 66.7% of members, and 60.9% had experience using intravitreal clindamycin. Corticosteroid drugs were administered systemically by 97.4%; 24.7% also injected corticosteroid intravitreally, almost always in combination with an antimicrobial drug (72.3%). The majority of members followed up all (60.4%) or selected (35.9%) patients after resolution of acute disease, and prophylaxis against recurrence with trimethoprim-sulfamethoxazole was prescribed to selected patients by 69.8%. Conclusion Our report presents a current management approach for ocular toxoplasmosis, as practised by a large international group of uveitis-specialised ophthalmologists