Enhancing Fundamental Robot-Assisted Surgical Proficiency by Using a Portable Virtual Simulator

Background. The development of a virtual reality (VR) training platform provides an affordable interface. The learning effect of VR and the capability of skill transfer from the VR environment to clinical tasks require more investigation. Methods. Here, 14 medical students performed 2 fundamental surgical tasks—bimanual carrying (BC) and peg transfer (PT)—in actual and virtual environments. Participants in the VR group received VR training, whereas participants in the control group played a 3D game. The learning effect was examined by comparing kinematics between pretraining and posttraining in the da Vinci Surgical System. Differences between VR and playing the 3D game were also examined. Results. Those who were trained with the VR simulator had significantly better performance in both actual PT (P = .002) and BC (P \u3c .001) tasks. The time to task completion and the total distance traveled were significantly decreased in both surgical tasks in the VR group compared with the 3D game group. However, playing the 3D game showed no significant enhancement of fundamental surgical skills in the actual PT task. The difference between pretraining and posttraining was significantly larger in the VR group than in the 3D game group in both the time to task completion (P = .002) and the total distance traveled (P = .027) for the actual PT task. Participants who played the 3D game seemed to perform even worse in posttraining. Conclusions. Training with the portable VR simulator improved robot-assisted surgical skill proficiency in comparison to playing a 3D game

Pattern of mRNA expression of β-defensins in basal cell carcinoma

BACKGROUND: Although the human β-defensins hBDs today seem to have diverse functional activities in innate antimicrobial immunity, a few reports also indicated an altered expression of these antimicrobial peptides (AMPs) in tissues of cancers such as oral squamous cell carcinoma. The present work was aimed on the study of hBD gene expression in basal cell carcinoma (BCC) which is the most common cancer in humans. METHODS: Twenty-two non-ulcerated BCCs (12 nodular type, 10 superficial type) have been analysed for the presence of hBD (1–3) mRNA by quantitative real-time RT-PCR. As controls, non-lesional skin specimens of BCC patients as well as samples of healthy subjects were assessed by RT-PCR. RESULTS: hBD-1 levels in healthy controls and non-lesional skin of BCC patients were significantly (P < 0.05) higher than the levels observed in tumour tissue. Moreover, BCCs showed significantly (P < 0.05) increased mRNA expression of hBD-2 as compared to controls. There was no significant (P > 0.05) difference between lesional mRNA levels for hBD-3 and those levels observed in controls. The mRNA expression of hBDs (1–3) found in nodular and superficial BCCs did not significantly (P > 0.05) differ. CONCLUSION: The gene expression patterns of hBD-1 and hBD-2 are for the first time shown to be significantly altered in non-ulcerated BCCs as compared to intra-individual and inter-individual controls, respectively. The present findings may indicate that beside the antimicrobial activity of AMPs, hBDs may also play a role in the pathogenesis of BCC. However, functional and immunohistological studies investigating hBDs in patients with BCC are needed to confirm our data

Spatio-temporal effects of an urban development announcement and its cancellation on house prices: A quasi-natural experiment

We use a spatio-temporal autoregressive difference-in-differences (SDID) framework to assess the strength of the effect, distributed across space and time, of announcements associated with urban development on house prices. We use a quasi-natural experiment of a large-scale urban redevelopment project in Seoul, South Korea, first announced in 2007 and cancelled six years later without any construction having taken place. Using a rich dataset comprising of 21,200 apartment transactions between 2006 and 2015, we find that the development announcement effect accounts for an increase in apartment transaction prices by up to 7.3% depending on the location of the property from the project site. Prices decrease by up to 5.2% following the cancellation of the project. The SDID captures significant spatial autoregressive effects accounting for up to 15% of the changes in transaction prices, reducing the announcement effects from a standard DID model

Nuclear magnetic resonance study of d-TGGCCA in solution.

The 1H NMR spectrum of a self complementary deoxyhexanucleotide (d-TGGCCA) in water solution has been completely and unambiguously assigned by use of two-dimensional techniques and phosphorus off-resonance decoupling experiments. The helix-coil transition has been monitored by following most of the non-exchangeable protons against temperature and was shown to be a cooperative dissociation-association process. Sequential fraying is sizable even at low temperature. Considerations of coupling constants and of Nuclear Overhauser effects show the helix to be of the B-DNA type

Largeurs partielles de transition pour les niveaux de spin J = 1 de 184W et 196Pt excités par la capture des neutrons intermédiaires

The J = 1 levels excited by resonance neutron capture have been studied for W and Pt. The relative transition probabilities to the ground state or to the first excited levels show some fluctuations from level to level. In order to analyze the distributions of the partial radiation width, it has been assumed, as Porter and Thomas did, that the correct distribution a χ2 distribution.On étudie les niveaux excités dans W et Pt par la capture des neutrons intermédiaires. Certaines fluctuations apparaissent, de résonance à résonance, pour les niveaux excités de spin J = 1 de 184W et 196Pt, dans les probabilités de transition radiative au niveau fondamental ou aux premiers niveaux excités. La distribution de ces fluctuations est discutée à la lumière de l'interprétation de Porter-Thomas