The Relation between the Radial Collapse and the Number of Metaphyseal Screws for Distal Radius Fractures.

Introduction: The purpose of this study is the evaluation of radial collapse, based on the number of screws used in the metaphyseal region and by distal dorsal distance (DDD) and lunate facet distance (LFD) measurement. Materials and methods: Between 2015 and 2019, 60 patients who were being treated with volar locking plates due to isolated distal radius fracture were evaluated. Control radiographs were taken on the first day and at 3rd-, 6th- and 12th-month follow-ups. Distal dorsal cortex distance and lunate facet distance were measured in the lateral radiographs. The number of screws used in the metaphyseal region was also evaluated. According to the number of screws, the amount of collapse was analysed based on both the LFD and the DDD. Results: The mean age of patients was 43.5±12.7 years. Thirty-three of the patients included in the study were male and 27 were female, and the minimum follow-up period was one year. According to the mean number of screws, groups were defined as up to 6 screws or 7 screws and above. There was a statistically significant difference between the groups in terms of DDD collapse at the 6th-month and 12th-month follow-ups (p<0.005). It was observed that the radial collapse and decrease in DDD and LFD were lower in plates with seven screws and above. Conclusion: Decreases in either DDD or LFD, or radial collapse were observed less in patients who had seven or more metaphyseal screws inserted. These findings might be useful for surgeons treating distal radius fractures to reduce radial collapse.

The Relation between the Radial Collapse and the Number of Metaphyseal Screws for Distal Radius Fractures

@#Introduction: The purpose of this study is the evaluation of radial collapse, based on the number of screws used in the metaphyseal region and by distal dorsal distance (DDD) and lunate facet distance (LFD) measurement. Materials and methods: Between 2015 and 2019, 60 patients who were being treated with volar locking plates due to isolated distal radius fracture were evaluated. Control radiographs were taken on the first day and at 3rd-, 6th- and 12th-month follow-ups. Distal dorsal cortex distance and lunate facet distance were measured in the lateral radiographs. The number of screws used in the metaphyseal region was also evaluated. According to the number of screws, the amount of collapse was analysed based on both the LFD and the DDD. Results: The mean age of patients was 43.5±12.7 years. Thirty-three of the patients included in the study were male and 27 were female, and the minimum follow-up period was one year. According to the mean number of screws, groups were defined as up to 6 screws or 7 screws and above. There was a statistically significant difference between the groups in terms of DDD collapse at the 6th-month and 12th-month follow-ups (p<0.005). It was observed that the radial collapse and decrease in DDD and LFD were lower in plates with seven screws and above. Conclusion: Decreases in either DDD or LFD, or radial collapse were observed less in patients who had seven or more metaphyseal screws inserted. These findings might be useful for surgeons treating distal radius fractures to reduce radial collapse.

Dark matter results from 100 live days of XENON100 data.

We present results from the direct search for dark matter with the XENON100 detector, installed underground at the Laboratori Nazionali del Gran Sasso of INFN, Italy. XENON100 is a two-phase time-projection chamber with a 62 kg liquid xenon target. Interaction vertex reconstruction in three dimensions with millimeter precision allows the selection of only the innermost 48 kg as the ultralow background fiducial target. In 100.9 live days of data, acquired between January and June 2010, no evidence for dark matter is found. Three candidate events were observed in the signal region with an expected background of (1.8 ± 0.6) events. This leads to the most stringent limit on dark matter interactions today, excluding spin-independent elastic weakly interacting massive particle (WIMP) nucleon scattering cross sections above 7.0 × 10(-45) cm(2) for a WIMP mass of 50 GeV/c(2) at 90% confidence level.

Spatially uniform calibration of a liquid xenon detector at low energies using (83m)Kr.

A difficult task with many particle detectors focusing on interactions below approximately 100 keV is to perform a calibration in the appropriate energy range that adequately probes all regions of the detector. Because detector response can vary greatly in various locations within the device, a spatially uniform calibration is important. We present a new method for calibration of liquid xenon (LXe) detectors, using the short-lived (83m)Kr. This source has transitions at 9.4 and 32.1 keV, and as a noble gas like Xe, it disperses uniformly in all regions of the detector. Even for low source activities, the existence of the two transitions provides a method of identifying the decays that is free of background. We find that at decreasing energies, the LXe light yield increases, while the amount of electric field quenching is diminished. Additionally, we show that if any long-lived radioactive backgrounds are introduced by this method, they will present less than 67x10(-6) events kg(-1) day(-1) keV(-1) in the next generation of LXe dark matter direct detection searches.

First dark matter results from the XENON100 experiment.

The XENON100 experiment, in operation at the Laboratori Nazionali del Gran Sasso in Italy, is designed to search for dark matter weakly interacting massive particles (WIMPs) scattering off 62 kg of liquid xenon in an ultralow background dual-phase time projection chamber. In this Letter, we present first dark matter results from the analysis of 11.17 live days of nonblind data, acquired in October and November 2009. In the selected fiducial target of 40 kg, and within the predefined signal region, we observe no events and hence exclude spin-independent WIMP-nucleon elastic scattering cross sections above 3.4 × 10⁻44 cm² for 55 GeV/c² WIMPs at 90% confidence level. Below 20 GeV/c², this result constrains the interpretation of the CoGeNT and DAMA signals as being due to spin-independent, elastic, light mass WIMP interactions.

An alternative method for cardioplegia delivery during totally endoscopic robotic surgery.

The optimal technique for myocardial protection and cardioplegia delivery during totally endoscopic robotic surgery is still under evolution. Cardioplegia delivery with endovascular clamping of the aorta is a common method used for this purpose but has several disadvantages and may lead to serious complications. Here we describe an alternative cardioplegia delivery method during totally endoscopic atrial septal defect closure and mitral valve repair. The method using a transthoracic aortic clamp and an antegrade cardioplegia cannula without any thoracotomy seems to be a safe and reproducible technique, which may enhance myocardial protection and prevent some of the complications of the endoclamp technique during robotically assisted cardiac surgery.

Stuck mechanical valve in pregnancy.

Mechanical heart valve thrombosis during pregnancy is a challenging condition. We present a pregnant patient with stuck mechanical mitral valve. During the 36th week of pregnancy, she was admitted to our emergency clinic because of aggravated dyspnea, tachypnea, and cyanosis. Echocardiography revealed stuck mechanical valve in mitral position and she was diagnosed with acute left ventricular heart failure due to mechanical valve thrombosis. Reoperative mitral valve replacement was performed in emergency conditions immediately following Cesarean section. She and her baby were discharged 11 days after surgery without complications.

Opioid peptides as possible neuromodulators in the frog peripheral nerve system.

Sciatic nerves of the frog Rana ridibunda were examined for the effects of applied opioid peptide, methionine-enkephalin, synthetic enkephalin analogue, leucine-enkephalin-NH(2) and opiate antagonist, naloxone. The effect of both peptides in concentrations of 1x10(-6) and 1x10(-5)M or naloxone in 1x10(-6)M was investigated on the action potential parameters using electrophysiological techniques. The isolated nerves were stimulated by single square pulses each of which lasted for 0.5ms at supramaximal strength. Effect of each single dose of peptides at 0min was compared with the remaining time segments. Both peptides produced changes in action potential of nerve when compared with untreated nerves. Methionine-enkephalin in both concentrations reduced the amplitude between 7% and 41% and conduction velocity at about 26-61%. This peptide in the same concentrations prolonged the duration around 12-53% and increased the stimulating voltage at about 9-50%. In contrast, leucine-enkephalin-NH(2) in both concentrations caused a decrease in amplitude between 13% and 48% and in conduction velocity around 20-50%. The same concentrations of this peptide prolonged the duration at about 3-33% and increased the stimulating voltage at about 10-56%, but naloxone in 1x10(-6)M antagonized the responses of both peptides over 75%. The results indicate that both opioid peptides produce changes in action potential parameters in frog peripheral nerve system and these changes are partially reversed by naloxone.

Evidence for the involvement of an opioid system in sciatic nerve of Rana ridibunda.

The effect of opioid peptide, D-alanine2-leucine-enkephalin and opioid homolog peptide, des-tyrosine-methionine-enkephalin in concentrations of 1 x 10(-6) and 1 x 10(-5) M was investigated on the action potential parameters of frog sciatic nerve. Des-tyrosine-methionine-enkephalin was used as the control to prove the opioid action of the peptide. The effects of both peptides were examined by means of the extracellular electrophysiological technique. The isolated sciatic nerves were stimulated by single square pulses each of which lasted for 0.5 ms at supramaximal strength. Effect of each single dose of peptides at 0 min was compared with the remaining time segments. Both peptides produced changes on action potential of Rana ridibunda sciatic nerve when compared with untreated nerves. D-alanine2-leucine-enkephalin decreased significantly the amplitude at about 34-83%, the area at about 34-92%. The same concentrations of this peptide decreased significantly the conduction velocity around 35-78%. In contrast, des-tyrosine-methionine-enkephalin reduced the action potential amplitude between 8% and 80%. The same concentrations of this peptide decreased significantly the area at about 12-76% and the conduction velocity around 42-70%. The depression of both peptides in action potential parameters was partially blocked by 1 x 10(-6) M naloxone.

Controlled micromanipulation of human sperm in three dimensions with an infrared laser optical trap: effect on sperm velocity.

Individual human sperm can be micromanipulated in three dimensions using a 1.06 microns Nd:YAG laser trap. Single sperm swimming with velocities in the range of 65 to 85 microns/sec can be trapped with 40 mW of power through 120 seconds without a deleterious effect on velocity. Even though it will be necessary to further evaluate the effects of laser light on specific functions of sperm, our data suggest that decreasing the time of manipulation to a minimum will increase the safety of the micromanipulation procedures. Laser traps may play a role in assisted reproductive technology by facilitating the selective transport of individual sperm.