Analysis of paediatric cochlear implant candidacy: Single centre, retrospective observational study

INTRODUCTION

The criteria for cochlear implantation can differ among countries or even among regions in the same country. Patient selection is important for the identification of those children who can benefit the most from cochlear implants. A number of patients who are possible cochlear implant candidates do not meet the assessment criteria; and some of these requirements are modifiable components.

MATERIALS AND METHODS

This single-centre, cross-sectional study used secondary data from 2014 until 2018. A consecutive sampling method was applied and a final sample size of 73 samples was achieved. Potential prelingual hearing loss candidates for cochlear implant aged less than 48 months old in Raja Permaisuri Bainun Hospital (HRPB), Ipoh Perak were included in this study. The candidacy selection outcome was analysed and reported as proportions. The associations between the evaluation criteria and outcome were examined using regression analysis.

RESULTS

Of the 73 potential candidates, only 17 (23%) were selected to receive cochlear implants. Bivariate analysis identified hearing compliance, behaviour, medical contraindications and family commitment as significantly associated with cochlear implant evaluation outcome. However, multivariate logistic regression revealed only family commitment as a significant predictor of the outcome of the implant candidacy evaluation (OR 44.7; 95%CI 3.11-643.4; p<0.005).

CONCLUSION

Family commitment, a modifiable element, was the key factor affecting the selection of candidates. Addressing the reasons for this effect could increase the number of potential candidates who ultimately receive implants.

[Feasibility, safety and long-term efficacy of laparoscopic total gastrectomy combined with distal pancreaticosplenectomy for T4b gastric cancer]

Objective: To explore the feasibility, safety and long-term efficacy of laparoscopic total gastrectomy combined with distal pancreaticosplenectomy for the treatment of T4b gastric cancer. Methods: A retrospective cohort study was performed. Clinical data of consecutive patients with T4b gastric cancer invading pancreatic tail undergoing laparoscopic or open total gastrectomy combined with distal pancreaticosplenectomy from January 2010 to December 2014 were analyzed retrospectively. Enrollment criteria: (1) primary gastric cancer confirmed by pathology as T4b adenocarcinoma; (2) chest+abdominal+pelvic enhanced CT indicated cancer invading pancreatic tail without distant metastasis, and R0 resection was evaluated as feasible before operation; (3) physical status was ECOG score 0 to 2, and was tolerant to operation. Patients with peritoneal implant metastasis and tumor invasion of other organs during operation, or changes in surgical methods for other reasons were excluded. All the operations were performed by the same surgical team, which had the experiences of more than 100 cases of laparoscopic and 100 cases of open radical gastrectomy with D2 lymph node dissection. The choice of surgical procedure was discussed by the surgeon and the patient, and decided according to the patient's intension. Patients were divided into the laparoscopic group and open group according to the surgical method. Intraoperative and perioperative findings were compared between the two groups. The 3-year disease-free survival rate were analyzed with Kaplan-Meier survival curve and compared by using log-rank test. Results: A total of 37 consecutive patients were enrolled, including 21 in the laparoscopic group and 16 in the open group, and no one receiving laparoscopic procedure was converted to open surgery. The baseline data of two groups were comparable (all P>0.05). Compared with the open group, the laparoscopic group had significantly longer operation time [(264.0±35.1) minutes vs. (226.6±49.9) minutes, t=2.685, P=0.011], significantly less intraoperative blood loss [(65.7±37.4) ml vs. (182.2±94.6) ml, t=-4.658, P<0.001], significantly shorter time to postoperative flatus [(2.8±0.7) days vs. (4.1±0.7) days, t=-5.776, P<0.001] and significantly shorter postoperative hospital stay [(13.3±2.8) days vs. (16.6±4.3) days, t=-2.822, P=0.008]. Morbidity of postoperative complications, including anastomotic leakage, pancreatic fistula, abdominal abscess, intraperitoneal hemorrhage and duodenal stump leakage, in two groups was similar [19.0% (4/21) vs. 4/16, P=0.705]. There were no cases of anastomotic bleeding or stenosis. The 30-day postoperative mortality was 0 in the laparoscopic group and 1/16 in the open group, respectively (P=0.432). The 3-year disease-free survival rates were 38.1% and 37.5% in the laparoscopic and open group, respectively (P=0.751). Conclusion: Laparoscopic total gastrectomy combined with distal pancreaticosplenectomy performed by experienced surgeons for T4b gastric cancer is safe and effective.

A transition-edge sensor-based x-ray spectrometer for the study of highly charged ions at the National Institute of Standards and Technology electron beam ion trap

We report on the design, commissioning, and initial measurements of a Transition-Edge Sensor (TES) x-ray spectrometer for the Electron Beam Ion Trap (EBIT) at the National Institute of Standards and Technology (NIST). Over the past few decades, the NIST EBIT has produced numerous studies of highly charged ions in diverse fields such as atomic physics, plasma spectroscopy, and laboratory astrophysics. The newly commissioned NIST EBIT TES Spectrometer (NETS) improves the measurement capabilities of the EBIT through a combination of high x-ray collection efficiency and resolving power. NETS utilizes 192 individual TES x-ray microcalorimeters (166/192 yield) to improve upon the collection area by a factor of ∼30 over the 4-pixel neutron transmutation doped germanium-based microcalorimeter spectrometer previously used at the NIST EBIT. The NETS microcalorimeters are optimized for the x-ray energies from roughly 500 eV to 8000 eV and achieve an energy resolution of 3.7 eV-5.0 eV over this range, a more modest (<2×) improvement over the previous microcalorimeters. Beyond this energy range, NETS can operate with various trade-offs, the most significant of which are reduced efficiency at lower energies and being limited to a subset of the pixels at higher energies. As an initial demonstration of the capabilities of NETS, we measured transitions in He-like and H-like O, Ne, and Ar as well as Ni-like W. We detail the energy calibration and data analysis techniques used to transform detector counts into x-ray spectra, a process that will be the basis for analyzing future data.

Testing three-body quantum electrodynamics with trapped Ti20+ ions: evidence for a Z-dependent divergence between experiment and calculation

We report a new test of quantum electrodynamics (QED) for the w (1s2p(1)P(1)→1s(2)(1)S(0)) x-ray resonance line transition energy in heliumlike titanium. This measurement is one of few sensitive to two-electron QED contributions. Systematic errors such as Doppler shifts are minimized in our experiment by trapping and stripping Ti atoms in an electron beam ion trap and by applying absolute wavelength standards to calibrate the dispersion function of a curved-crystal spectrometer. We also report a more general systematic discrepancy between QED theory and experiment for the w transition energy in heliumlike ions for Z>20. When all of the data available in the literature for Z=16-92 are taken into account, the divergence is seen to grow as approximately Z(3) with a statistical significance on the coefficient that rises to the level of 5 standard deviations. Our result for titanium alone, 4749.85(7) eV for the w line, deviates from the most recent ab initio prediction by 3 times our experimental uncertainty and by more than 10 times the currently estimated uncertainty in the theoretical prediction.

The 3C/3D line ratio in Ni XIX: New Ab Initio theory and experimental results

We report a fully relativistic close-coupling calculation of the electron impact excitation of Ni xix to derive the 3C/3D line intensity ratio, with an uncertainty of 5%. Convergence of the calculation with respect to both channel coupling effects and the many interacting Rydberg series of resonances has been achieved. New measurements in an electron beam ion trap agree with our calculation. We show that the 3C/3D x-ray line ratio depends sensitively on both electron energy and beamwidth in an optically thin plasma. Accounting for this dependence improves the accuracy of the Ni abundance determination in astrophysical sources.

Driven production of cold antihydrogen and the first measured distribution of antihydrogen states

Cold antihydrogen is produced when antiprotons are repeatedly driven into collisions with cold positrons within a nested Penning trap. Efficient antihydrogen production takes place during many cycles of positron cooling of antiprotons. A first measurement of a distribution of antihydrogen states is made using a preionizing electric field between separated production and detection regions. Surviving antihydrogen is stripped in an ionization well that captures and stores the freed antiproton for background-free detection.

Background-free observation of cold antihydrogen with field-ionization analysis of its states

A background-free observation of cold antihydrogen atoms is made using field ionization followed by antiproton storage, a detection method that provides the first experimental information about antihydrogen atomic states. More antihydrogen atoms can be field ionized in an hour than all the antimatter atoms that have been previously reported, and the production rate per incident high energy antiproton is higher than ever observed. The high rate and the high Rydberg states suggest that the antihydrogen is formed via three-body recombination.

Field ionization of strongly magnetized rydberg positronium: A new physical mechanism for positron accumulation

Magnetized Rydberg positronium forms when an energetic positron ( e(+)) slows within a tungsten crystal and picks up an electron ( e(-)) as it emerges in a strong magnetic field. The signature is equal numbers of e(+) and e(-) when a weak electric field is applied, either of which can be accumulated and counted. The new e(+) accumulation technique is simple, robust, and much more efficient than any other demonstrated to be compatible with a cryogenic vacuum. Possible applications include the study of cold single component plasmas of e(+) and the formation of cold antihydrogen.

Bragg diffraction from crystallized ion plasmas

Single crystals of a one-component plasma were observed by optical Bragg diffraction. The plasmas contained 10(5) to 10(6) single-positive beryllium-9 ions (9Be+) at particle densities of 10(8) to 10(9) per cubic centimeter. In approximately spherical plasmas, single body-centered cubic (bcc) crystals or, in some cases, two or more bcc crystals having fixed orientations with respect to each other were observed. In some oblate plasmas, a mixture of bcc and face-centered cubic ordering was seen. Knowledge of the properties of one-component plasma crystals is required for models of white dwarfs and neutron stars, which are believed to contain matter in that form.