Search for Boosted Dark Matter in COSINE-100

We search for energetic electron recoil signals induced by boosted dark matter (BDM) from the galactic center using the COSINE-100 array of NaI(Tl) crystal detectors at the Yangyang Underground Laboratory. The signal would be an excess of events with energies above 4 MeV over the well-understood background. Because no excess of events are observed in a 97.7  kg·yr exposure, we set limits on BDM interactions under a variety of hypotheses. Notably, we explored the dark photon parameter space, leading to competitive limits compared to direct dark photon search experiments, particularly for dark photon masses below 4 MeV and considering the invisible decay mode. Furthermore, by comparing our results with a previous BDM search conducted by the Super-Kamionkande experiment, we found that the COSINE-100 detector has advantages in searching for low-mass dark matter. This analysis demonstrates the potential of the COSINE-100 detector to search for MeV electron recoil signals produced by the dark sector particle interactions.

A Nationwide Study on the Impact of COVID-19 Pandemic on Volume of Spine Surgery in South Korea

Objective

In March 2020, World Health Organization declared a global pandemic caused by a novel coronavirus (SARS-CoV-2). The disease caused by this virus is called COVID-19. Due to its high contagiousness, many changes have occurred in overall areas of our daily life including hospital use by patients. The aim of this study was to investigate the impact of COVID-19 on volume of spine surgery in South Korea using the National Health Insurance database and compare it with the volume of a homologous period before the pandemic.

Methods

Data of related to spine surgery from January 2019 to April 2021 were obtained from the National Health Insurance and Health Insurance Review and Assessment Service database. Primary outcomes were total number of patients, rate of patients per 100000 population, and total number of procedures. The number of patients by hospital size was also analyzed.

Results

COVID-19 outbreaks occurred in South Korea in March, August, and December of 2020. Compared to the previous year, the total number of patients who underwent spinal surgery showed a decrease for 2–3 months after the first and second outbreaks. However, it showed an increasing trend after the third outbreak. The same pattern was observed in terms of the ratio of the number of patients per 100000 population. Between 2019 and 2021, the mean number of spine surgeries per month tended to increase. Mean annual medical expenses increased over the years (p=0.001). When the number of spine surgeries was analyzed by hospital size, proportion of tertiary general hospital in 2021 increased compared to those in 2019 and 2020 (vs. 2019, p=0.012; vs. 2020, p=0.016). The proportion of general hospital was significantly decreased in 2020 compared to that in 2019 (p=0.037).

Conclusion

After the COVID-19 outbreak, patients tended to postpone spinal surgery temporarily. The number of spinal surgeries decreased for 2–3 months after the first and second outbreaks. However, as the ability to respond to the COVID-19 pandemic at the hospital and society-wide level gradually increased, the number of spine surgeries did not decrease after the third outbreak in December 2020. In addition, the annual number of spine surgeries continued to increase. However, it should be noted that patients tend to be increasingly concentrated in tertiary hospitals for spinal surgery.

Interchangeability for Biologics is a Legal Distinction in the USA, Not a Clinical One

Biologics are increasingly vital medicines that significantly reduce morbidity as well as mortality, yet access continues to be an issue even in apparently wealthy countries, such as the USA. While patient access is expected to improve with the introduction of biosimilars, misperceptions in a significant part based on terminology continue to make a sustained contribution by biosimilars difficult. Patients are and will continue to suffer needlessly if biosimilars continue to be impugned. Consequently, it is increasingly urgent that semantics are clarified, and in particular, the implication that interchangeable biologics are better biosimilars dismissed. This paper distinguishes between the real differences between biologics that matter clinically to patients and discusses the actual meaning of a US Food and Drug Administration designation of interchangeability for a biosimilar product. This will help highlight where there is need for further Food and Drug Administration education and which stakeholders likely need that education the most.

Central Sarcopenia, Frailty and Comorbidity as Predictor of Surgical Outcome in Elderly Patients with Degenerative Spine Disease

Objective

People are living longer and the elderly population continues to increase. The incidence of degenerative spinal diseases (DSDs) in the elderly population is quite high. Therefore, we are facing more cases of DSD and offering more surgical solutions in geriatric patients. Understanding the significance and association of frailty and central sarcopenia as risk factors for spinal surgery in elderly patients will be helpful in improving surgical outcomes. We conducted a retrospective cohort analysis of prospectively collected data to assess the impact of preoperative central sarcopenia, frailty, and comorbidity on surgical outcome in elderly patients with DSD.

Methods

We conducted a retrospective analysis of patients who underwent elective spinal surgery performed from January 1, 2019 to September 30, 2020 at our hospital. We included patients aged 65 and over who underwent surgery on the thoracic or lumbar spine and were diagnosed as DSD. Central sarcopenia was measured by the 50th percentile of psoas : L4 vertebral index (PLVI) using the cross-sectional area of the psoas muscle. We used the Korean version of the fatigue, resistance, ambulation, illnesses, and loss of weight (K-FRAIL) scale to measure frailty. Comorbidity was confirmed and scored using the Charlson Comorbidity Index (CCI). As a tool for measuring surgical outcome, we used the Clavien-Dindo (CD) classification for postoperative complications and the length of stay (LOS).

Results

This study included 85 patients (35 males and 50 females). The mean age was 74.05±6.47 years. Using the K-FRAIL scale, four patients were scored as robust, 44 patients were pre-frail and 37 patients were frail. The mean PLVI was 0.61±0.19. According to the CD classification, 50 patients were classified as grade 1, 19 as grade 2, and four as grade 4. The mean LOS was 12.35±8.17 days. Multivariate stepwise regression analysis showed that postoperative complication was significantly associated with surgical invasiveness and K-FRAIL scale. LOS was significantly associated with surgical invasiveness and CCI. K-FRAIL scale showed a significant correlation with CCI and PLVI.

Conclusion

The present study demonstrates that frailty, comorbidity, and surgical invasiveness are important risk factors for postoperative complications and LOS in elderly patients with DSD. Preoperative recognition of these factors may be useful for perioperative optimization, risk stratification, and patient counseling.

Clinical characteristics and differences among 802 acral tumors by anatomical sites

BACKGROUND

Acral skin tumors are common, but there are few literature reviews regarding their incidence.

OBJECTIVES

To investigate the clinical characteristics and differences in incidence of benign and malignant acral tumors by anatomical site.

METHODS

A retrospective review of 802 patients with acral skin tumors confirmed by skin biopsy between January 2010 and December 2019 was conducted. Age, sex, duration, symptoms, and sites were obtained from medical records and photographs.

RESULTS

The mean age of onset was 43.8 years with a male-to-female ratio of 1:1.41, and the mean duration was 68.8 months. Most were asymptomatic (66.7%). In total, 802 acral tumors were identified: 512 (63.8%) were benign and 290 (36.2%) were malignant. The most common benign tumors were benign melanocytic lesions (n = 239), and the most common malignant tumors were melanoma (n = 234). The most common site was the sole (n = 408). Benign melanocytic lesions, melanoma, and epidermal cyst were more frequent on the foot, and pyogenic granuloma, glomus tumor, hemangioma, and mucous cyst were more frequent on the hand. Glomus tumor, fibroma, mucous cyst, and osteoma were more frequent on the nail portion, and benign melanocytic lesions and epidermal cyst were more frequent on the non-nail portion.

CONCLUSIONS

This study reports the incidence of various benign and malignant acral tumors according to site, and we believe the results will be helpful in making a diagnosis in the clinic.

Disappearance of Arachnoid Cyst after Burrhole Trephination: Case Series

We report 3 cases of arachnoid cysts (ACs) that completely disappeared after burr hole drainage, without cyst fenestration into the subarachnoid space or cystoperitoneal shunt. The first patient was a 21-year-old female with an AC of the right cerebral convexity, found incidentally. After endoscopic AC fenestration was performed, the patient complained of persistent headache. Two-month postoperative brain imaging revealed reaccumulated AC and associated multi-stage subdural hematoma. Burr hole drainage was performed to resolve the chronic subdural hematoma (CSDH). Three months later, brain computed tomography showed that the CSDH and the AC had disappeared. The second patient was an 11-year-old male who had a history of trauma 1 month prior to presentation at the clinic. Brain magnetic resonance imaging revealed an AC in the left sylvian fissure with CSDH. We performed burr hole drainage to treat the CSDH first. Subsequently, the AC as well as the CSDH disappeared. The third case was an AC of the right parietal convexity, found incidentally. Only burr hole drainage was performed, following which, the AC disappeared. This case series shows that an AC can disappear naturally after rupture into the subdural space by trauma or the burr hole procedure.

Current Training Status of Neurosurgical Residents in South Korea: A Nationwide Multicenter Survey

BACKGROUND

In South Korea, special legislation was introduced in December 2016 to limit residents' training time to a maximum of 80 hours per week. The aim of this study was to survey the current training system and environment of neurosurgical residents and to find ways to improve the quality of neurosurgical training.

METHODS

The questionnaire survey included 373 neurosurgical residents at 66 training hospitals nationwide, who were members of the Korean Neurosurgical Society. The survey method included a questionnaire link through a text message and was carried out anonymously. The survey was conducted for 7 days and targeted a total of 106 residents (28.4%).

RESULTS

Most respondents selected "excessive training time" as a reason for dissatisfaction with the training environment (n = 61, 57.5%), followed by "limited number of opportunities for surgery" (n = 50, 47.2%), and "little experience for research" (n = 42, 39.6%). Respondents still believe that they have to work excessively longer, even after 80 hours of training per week.

CONCLUSIONS

The major reason that neurosurgical residents are dissatisfied with the current training system and environment is the excessive time spent on it. These survey results are expected to be used as the basis for improvement of the residents' training system and work environment in South Korea.

Search for a Dark Matter-Induced Annual Modulation Signal in NaI(Tl) with the COSINE-100 Experiment

We present new constraints on the dark matter-induced annual modulation signal using 1.7 years of COSINE-100 data with a total exposure of 97.7 kg yr. The COSINE-100 experiment, consisting of 106 kg of NaI(Tl) target material, is designed to carry out a model-independent test of DAMA/LIBRA's claim of WIMP discovery by searching for the same annual modulation signal using the same NaI(Tl) target. The crystal data show a 2.7  cpd/kg/keV background rate on average in the 2-6 keV energy region of interest. Using a χ-squared minimization method we observe best fit values for modulation amplitude and phase of 0.0092±0.0067  cpd/kg/keV and 127.2±45.9  d, respectively.

First Direct Search for Inelastic Boosted Dark Matter with COSINE-100

A search for inelastic boosted dark matter (IBDM) using the COSINE-100 detector with 59.5 days of data is presented. This relativistic dark matter is theorized to interact with the target material through inelastic scattering with electrons, creating a heavier state that subsequently produces standard model particles, such as an electron-positron pair. In this study, we search for this electron-positron pair in coincidence with the initially scattered electron as a signature for an IBDM interaction. No excess over the predicted background event rate is observed. Therefore, we present limits on IBDM interactions under various hypotheses, one of which allows us to explore an area of the dark photon parameter space that has not yet been covered by other experiments. This is the first experimental search for IBDM using a terrestrial detector.

A large-aperture strip-grid beam splitter for partially combined two millimeter-wave diagnostics on Korea Superconducting Tokamak Advanced Research

A large-aperture beam splitter has been developed for simultaneous operation of two millimeter-wave diagnostics employing different probe beams in the frequency and polarization, microwave imaging reflectometer (∼85 GHz X-mode), and collective scattering system (300 GHz O-mode), on the Korea Superconducting Tokamak Advanced Research device. The beam splitter was designed based on a polarizer concept (i.e., grid of metal strips on a thin dielectric sheet), and this can be an optimal solution for these two diagnostics. Fabrication of the strips with uniform sub-millimeter width and spacing on a large dielectric sheet was achieved with an etching technique, and the laboratory test results on the reflection and transmission ratio are in good agreement with design values.

Standardisation of defined approaches for skin sensitisation testing to support regulatory use and international adoption: position of the International Cooperation on Alternative Test Methods

Skin sensitisation is the regulatory endpoint that has been at the centre of concerted efforts to replace animal testing in recent years, as demonstrated by the Organisation for Economic Co-operation and Development (OECD) adoption of five non-animal methods addressing mechanisms under the first three key events of the skin sensitisation adverse outcome pathway. Nevertheless, the currently adopted methods, when used in isolation, are not sufficient to fulfil regulatory requirements on the skin sensitisation potential and potency of chemicals comparable to that provided by the regulatory animal tests. For this reason, a number of defined approaches integrating data from these methods with other relevant information have been proposed and documented by the OECD. With the aim to further enhance regulatory consideration and adoption of defined approaches, the European Union Reference Laboratory for Alternatives to Animal testing in collaboration with the International Cooperation on Alternative Test Methods hosted, on 4-5 October 2016, a workshop on the international regulatory applicability and acceptance of alternative non-animal approaches, i.e., defined approaches, to skin sensitisation assessment of chemicals used in a variety of sectors. The workshop convened representatives from more than 20 regulatory authorities from the European Union, United States, Canada, Japan, South Korea, Brazil and China. There was a general consensus among the workshop participants that to maximise global regulatory acceptance of data generated with defined approaches, international harmonisation and standardisation are needed. Potential assessment criteria were defined for a systematic evaluation of existing defined approaches that would facilitate their translation into international standards, e.g., into a performance-based Test Guideline. Informed by the discussions at the workshop, the ICATM members propose practical ways to further promote the regulatory use and facilitate adoption of defined approaches for skin sensitisation assessments.

Detecting Dark Photons with Reactor Neutrino Experiments

We propose to search for light U(1) dark photons, A^{'}, produced via kinetically mixing with ordinary photons via the Compton-like process, γe^{-}→A^{'}e^{-}, in a nuclear reactor and detected by their interactions with the material in the active volumes of reactor neutrino experiments. We derive 95% confidence-level upper limits on ε, the A^{'}-γ mixing parameter, ε, for dark-photon masses below 1 MeV of ε<1.3×10^{-5} and ε<2.1×10^{-5}, from NEOS and TEXONO experimental data, respectively. This study demonstrates the applicability of nuclear reactors as potential sources of intense fluxes of low-mass dark photons.

Sterile Neutrino Search at the NEOS Experiment

An experiment to search for light sterile neutrinos is conducted at a reactor with a thermal power of 2.8 GW located at the Hanbit nuclear power complex. The search is done with a detector consisting of a ton of Gd-loaded liquid scintillator in a tendon gallery approximately 24 m from the reactor core. The measured antineutrino event rate is 1976 per day with a signal to background ratio of about 22. The shape of the antineutrino energy spectrum obtained from the eight-month data-taking period is compared with a hypothesis of oscillations due to active-sterile antineutrino mixing. No strong evidence of 3+1 neutrino oscillation is found. An excess around the 5 MeV prompt energy range is observed as seen in existing longer-baseline experiments. The mixing parameter sin^{2}2θ_{14} is limited up to less than 0.1 for Δm_{41}^{2} ranging from 0.2 to 2.3 eV^{2} with a 90% confidence level.

Compact ECEI system with in-vessel reflective optics for WEST

An electron cyclotron emission imaging (ECEI) diagnostic system for WEST (W Environment for Steady state Tokamak) is under development to study the MHD instabilities affected by tungsten impurities. The system will provide 2-D T_e fluctuation images (width × height = ∼18 cm × ∼ 34 cm at low field side and ∼13 cm × ∼ 39 cm at high field side) from a poloidal cross section with high spatial (≤1.7 cm) and temporal (≤2 μs) resolutions. While the key concept and electronic structure are similar to that of prior ECEI systems on other tokamak devices such as KSTAR, DIII-D, or ASDEX-U, part of the imaging optics have to be placed inside the vacuum vessel in order to resolve issues on limited installation space and longer beam path to the detector position. The in-vessel optics consisting of two large curvature-radius mirrors are expected to withstand the extreme heating on long-pulse operation scenario (∼1000 s). The out-vessel optical housing is constructed as compact as possible to remove easily from the installation site in case of necessity. Commissioning of the system is scheduled on the second experimental WEST campaign end of 2017.

Ion gyroscale fluctuation measurement with microwave imaging reflectometer on KSTAR

Ion gyroscale turbulent fluctuations with the poloidal wavenumber k_θ ∼ 3 cm^-1 have been measured in the core region of the neutral beam (NB) injected low confinement (L-mode) plasmas on Korea superconducting tokamak advanced research. The turbulence poloidal wavenumbers are deduced from the frequencies and poloidal rotation velocities in the laboratory frame, measured by the multichannel microwave imaging reflectometer. Linear and nonlinear gyrokinetic simulations also predict the unstable modes with the normalized wavenumber k_θρ_s ∼ 0.4, consistent with the measurement. Comparison of the measured frequencies with the intrinsic mode frequencies from the linear simulations indicates that the measured ones are primarily due to the E × B flow velocity in the NB-injected fast rotating plasmas.

New compact and efficient local oscillator optic system for the KSTAR electron cyclotron emission imaging system

Electron cyclotron emission imaging (ECEI) diagnostic on Korean Superconducting Tokamak Advanced Research utilizes quasi-optical heterodyne-detection method to measure 2D (vertical and radial) T_e fluctuations from two toroidally separated poloidal cross section of the plasma. A cylindrical lens local oscillator (LO) optics with optical path length (OPL) 2-2.5 m has been used in the current ECEI system to couple the LO source to the 24 vertically aligned array of ECE detectors. For efficient and compact LO optics employing the Powell lens is proposed so that the OPL of the LO source is significantly reduced from ∼2.0 m to 0.4 m with new optics. The coupling efficiency of the LO source is expected to be improved especially at the edge channels. Results from the optical simulation together with the laboratory test of the prototype optics will be discussed in this paper.

Comparing Risk-adjusted Hospital Mortality for CABG and AMI Patients

The objectives of this study were to compare the risk-adjusted mortality of coronary artery bypass graft (CABG) and acute myocardial infarction (AMI) patients simultaneously in six hospitals in Seoul, Korea, and to investigate the relationship between these performance measures by developing a predictive model of mortality. The medical records of 749 AMI and 564 CABG patients were reviewed. A predictive model was developed using logistic regression, including 170 variables selected as risk factors for risk adjustment. The validity of our predictive model was demonstrated to be within an acceptable range. The results showed that one hospital with a significantly low AMI mortality rate also had a low CABG mortality rate, while another hospital with a significantly high AMI mortality rate also had a high CABG mortality rate. Our results implied that hospitals providing good-quality medical management of coronary artery disease also provided a good-quality surgical service.

Design of a collective scattering system for small scale turbulence study in Korea Superconducting Tokamak Advanced Research

The design characteristics of a multi-channel collective (or coherent) scattering system for small scale turbulence study in Korea Superconducting Tokamak Advanced Research (KSTAR), which is planned to be installed in 2017, are given in this paper. A few critical issues are discussed in depth such as the Faraday and Cotton-Mouton effects on the beam polarization, radial spatial resolution, probe beam frequency, polarization, and power. A proper and feasible optics with the 300 GHz probe beam, which was designed based on these issues, provides a simultaneous measurement of electron density fluctuations at four discrete poloidal wavenumbers up to 24 cm(-1). The upper limit corresponds to the normalized wavenumber kθρe of ∼0.15 in nominal KSTAR plasmas. To detect the scattered beam power and extract phase information, a quadrature detection system consisting of four-channel antenna/detector array and electronics will be employed.

Post calibration of the two-dimensional electron cyclotron emission imaging instrument with electron temperature characteristics of the magnetohydrodynamic instabilities

The electron cyclotron emission imaging (ECEI) instrument is widely used to study the local electron temperature (Te) fluctuations by measuring the ECE intensity IECE ∝ Te in tokamak plasmas. The ECEI measurement is often processed in a normalized fluctuation quantity against the time averaged value due to complication in absolute calibration. In this paper, the ECEI channels are relatively calibrated using the flat Te assumption of the sawtooth crash or the tearing mode island and a proper extrapolation. The 2-D relatively calibrated electron temperature (Te,rel) images are reconstructed and the displacement amplitude of the magnetohydrodynamic modes can be measured for the accurate quantitative growth analysis.

Comparative Analysis of Efficacy and Safety of Multisession Radiosurgery to Single Dose Radiosurgery for Metastatic Brain Tumors

Background

The purpose of this study is to compare the efficacy and safety of multisession radiosurgery to those of single dose radiosurgery for metastatic brain tumors.

Methods

Between February 2008 and February 2012, 90 patients with 196 metastatic brain tumors were treated with cyberknife radiosurgery, and we reviewed these patients retrospectively. Among them, 57 patients underwent single dose radiosurgery, and 33 patients multisession radiosurgery. Tumors involving the eloquent area and large tumors (>5 cc) were treated with multisession radiosurgery. The median tumor volume and the median treatment dose of single dose radiosurgery were 2.05±0.72 cc and 19.76±1.54 Gy respectively, and in the case of multisession radiosurgery, 5.30±1.70 cc and 29.6±1.70 Gy respectively. The frequency of multisession dose was 3 to 5 times, on average 3.55 times, and 8.91 Gy were given per 1 session on average.

Results

The overall survival (OS) of multisession radiosurgery was 16.0 months, whereas that of single dose radiosurgery was 11.5 months. The radiologic tumor response rates were 90% in single dose radiosurgery and 95.4% in multisession radiosurgery, respectively. Over 6-month and 1-year periods, the OS rates of single dose radiosurgery were 71.4% and 44.9%, whereas those of multisession radiosurgery were 69.1% and 58.3%, respectively (p=0.83). Toxicities were seen in 18.1% in the single dose radiosurgery group versus 4% in the multisession radiosurgery group. The difference was significant (p<0.05).

Conclusion

In this study, the multisession radiosurgery group, despite the location and size constraints, did not differ from the single dose radiosurgery group when comparing the survival and recurrence rates, but complications and toxicity were lower. Thus, multisession radiosurgery is thought to be beneficial for treatment of large tumors and tumors located in the eloquent area.

Classification by causes of dark circles and appropriate evaluation method of dark circles

BACKGROUND

Dark circles refer to a symptom that present darkness under the eyes. Because of improvement in the quality of life, the dark circles have been recognized as one of major cosmetic concerns. However, it is not easy to classify the dark circles because they have various causes.

METHODS

To select suitable instruments and detailed evaluation items, the dark circles were classified according to the causes through visual assessment, Wood's lamp test, and medical history survey for 100 subjects with dark circles. After the classification, were newly recruited for instrument conformity assessment. Through this, suitable instruments for dark circle evaluation were selected. We performed a randomized clinical trial for dark circles, a placebo-controlled double-blind study, using effective parameters of the instruments selected from the preliminary test.

RESULTS

Dark circles of vascular type (35%) and mixed type (54%), a combination of pigmented and vascular types, were the most common. Twenty four subjects with the mixed type dark circles applied the test product (Vitamin C 3%, Vitamin A 0.1%, Vitamin E 0.5%) and placebo on randomized split-face for 8 weeks. The effective parameters (L*, a, M.I., E.I., quasi L*, quasi a* and dermal thickness) were measured during the study period. Result showed that the L* value of Chromameter(®) , Melanin index (M.I.) of Mexameter(®) and quasi L* value obtained by image analysis improved with statistical significance after applying the test product compared with the placebo product.

CONCLUSION

We classified the dark circles according to the causes of the dark circles and verified the reliability of the parameter obtained by the instrument conformity assessment used in this study through the efficacy evaluation. Also based on this study, we were to suggest newly established methods which can be applied to the evaluation of efficacy of functional cosmetics for dark circles.

Quasi 3D ECE imaging system for study of MHD instabilities in KSTAR

A second electron cyclotron emission imaging (ECEI) system has been installed on the KSTAR tokamak, toroidally separated by 1/16th of the torus from the first ECEI system. For the first time, the dynamical evolutions of MHD instabilities from the plasma core to the edge have been visualized in quasi-3D for a wide range of the KSTAR operation (B0 = 1.7∼3.5 T). This flexible diagnostic capability has been realized by substantial improvements in large-aperture quasi-optical microwave components including the development of broad-band polarization rotators for imaging of the fundamental ordinary ECE as well as the usual 2nd harmonic extraordinary ECE.

Measurement of the branching fraction B(Λc+ → pK-π+)

We present the first model-independent measurement of the absolute branching fraction of the Λ(c)(+) → pK(-)π(+) decay using a data sample of 978 fb(-1) collected with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. The number of Λ(c)(+) baryons is determined by reconstructing the recoiling D((*)-) pπ(+) system in events of the type e(+)e(-) → D((*)-) pπ(+)Λ(c)(+). The branching fraction is measured to be B(Λ(c)(+) → pK(-)π(+)) = (6.84 ± 0.24(-0.27)(+0.21))%, where the first and second uncertainties are statistical and systematic, respectively.

Microdecompression in spinal stenosis: a review

A goal of surgical treatment is to effectively treat pathology with minimizing injury of normal tissue. Microdecompression techniques are traditionally defined as procedures performed with a small incision using magnification and minimization of destruction to non-pathologic tissues. The good candidates are patients diagnosed of spinal stenosis who fail an appropriate course of non-operative management. These patients should have radiographic evidence of localized spinal stenosis without associated structural instability. Various techniques of microdecompression have been introduced until now. Although more technically challenging, microdecompression have produced long-lasting favorable outcomes via proper patient selection and surgeon training. In addition, the minimally invasive access techniques can greaten the results of microdecompression in the acute postoperative period. Through advanced minimally invasive techniques, the microdecompression will evolve in the future for sure.

Toroidal mode number estimation of the edge-localized modes using the KSTAR 3-D electron cyclotron emission imaging system

A new and more accurate technique is presented for determining the toroidal mode number n of edge-localized modes (ELMs) using two independent electron cyclotron emission imaging (ECEI) systems in the Korea Superconducting Tokamak Advanced Research (KSTAR) device. The technique involves the measurement of the poloidal spacing between adjacent ELM filaments, and of the pitch angle α* of filaments at the plasma outboard midplane. Equilibrium reconstruction verifies that α* is nearly constant and thus well-defined at the midplane edge. Estimates of n obtained using two ECEI systems agree well with n measured by the conventional technique employing an array of Mirnov coils.

Crowned dens syndrome: a case report and review of the literature

The crowned dens syndrome (CDS), also known as periodontoid calcium pyrophosphate dehydrate crystal deposition disease, is typified clinically by severe cervical pain, neck stiffness and atlantoaxial synovial calcification which could be misdiagnosed as meningitis, epidural abscess, polymyalgia rheumatica, giant cell arthritis, rheumatoid arthritis, cervical spondylitis or metastatic spinal tumor. Crystalline deposition on cervical vertebrae is less well known disease entity and only a limited number of cases have been reported to date. Authors report a case of CDS and describe the clinical feature.

Observation of D0-D0 mixing in e+e- collisions

We observe D(0)-D(0) mixing in the decay D(0) → K+π- using a data sample of integrated luminosity 976 fb(-1) collected with the Belle detector at the KEKB e+e- asymmetric-energy collider. We measure the mixing parameters x'(2) = (0.09 ± 0.22) × 10(-3) and y'=(4.6 ± 3.4) × 10(-3) and the ratio of doubly Cabibbo-suppressed to Cabibbo-favored decay rates R(D) = (3.53 ± 0.13) × 10(-3), where the uncertainties are statistical and systematic combined. Our measurement excludes the no-mixing hypothesis at the 5.1 standard deviation level.

Measurement of the τ-lepton lifetime at Belle

The lifetime of the τ lepton is measured using the process e+ e- → τ+ τ- , where both τ leptons decay to 3πν(τ). The result for the mean lifetime, based on 711  fb(-1) of data collected with the Belle detector at the ϒ(4S) resonance and 60  MeV below, is τ=(290.17±0.53(stat)±0.33(syst))×10(-15)  s. The first measurement of the lifetime difference between τ+ and τ- is performed. The upper limit on the relative lifetime difference between positive and negative τ leptons is |Δτ|/τ<7.0×10(-3) at 90% C.L.

Mid-long term effect of non-ablative high radiofrequency therapy on the rabbit dermal extracellular matrix

This study quantitatively investigated the postoperative effects of radiofrequency (RF) application on the normal dermal extracellular matrix (ECM) of in vivo rabbits. Postoperative effects were evaluated by histology and atomic force microscopy analysis of dermal tissues treated using three RF energy levels (10 ~ 30 W) and either a single- or multiple-pass procedure. Progressive changes in the morphology of rabbit dermal ECMs were investigated over a 30-day postoperartive period. All RF-treated groups, except for the low energy group (10 W), displayed more prominent inflammatory responses compared to the control. This inflammatory reaction was more prominent a day after application. Dermal tissues 30 days after RF application exhibited prominent myofibroblast activity associated with ECM contractile activity during wound healing in addition to chronic inflammation. A decrease in the morphology of dermal ECMs after RF application continued until seven days postoperatively. The ECM diameter increased to near baseline at 30 days postoperatively. Low energy and multi-pass applications resulted in greater collagen fibril contraction and recovery at the ultra-structural level at 30 days postoperatively than did a single high energy application.

Search for bottomonium states in exclusive radiative Υ(2S) decays

We search for bottomonium states in Υ(2S) → (bb)γ decays with an integrated luminosity of 24.7  fb(-1) recorded at the Υ(2S) resonance with the Belle detector at KEK, containing (157.8±3.6)×10(6) Υ(2S) events. The (bb) system is reconstructed in 26 exclusive hadronic final states composed of charged pions, kaons, protons, and K(S)(0) mesons. We find no evidence for the state recently observed around 9975 MeV (X(bb)) in an analysis based on a data sample of 9.3×10(6) Υ(2S) events collected with the CLEO III detector. We set a 90% confidence level upper limit on the branching fraction B[Υ(2S) → X(bb)γ] × ∑(i)B[X(bb) → h(i)] < 4.9×10(-6), summed over the exclusive hadronic final states employed in our analysis. This result is an order of magnitude smaller than the measurement reported with CLEO data. We also set an upper limit for the ηb(1S) state of B[Υ(2S) → ηb(1S)γ] × ∑(i)B[ηb(1S) → h(i)] < 3.7×10(-6).

Precision measurement of charged pion and kaon differential cross sections in e+ e- annihilation at sqrt[s]=10.52 GeV

Measurements of inclusive differential cross sections for charged pion and kaon production in e+ e- annihilation have been carried out at a center-of-mass energy of sqrt[s]=10.52  GeV. The measurements were performed with the Belle detector at the KEKB e+ e- collider using a data sample containing 113×10(6) e+ e- → qq events, where q={u,d,s,c}. We present charge-integrated differential cross sections dσ(h±)/dz for h±={π±,K±} as a function of the relative hadron energy z=2E(h)/sqrt[s] from 0.2 to 0.98. The combined statistical and systematic uncertainties for π± (K±) are 4% (4%) at z∼0.6 and 15% (24%) at z∼0.9. The cross sections are the first measurements of the z dependence of pion and kaon production for z>0.7 as well as the first precision cross section measurements at a center-of-mass energy far below the Z0 resonance used by the experiments at LEP and SLC.

Evidence of a new narrow resonance decaying to χ(c1)γ in B→χ(c1)γK

We report measurements of B→χ(c1)γK and χ(c2)γK decays using 772×10(6) BB[over ¯] events collected at the Υ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. Evidence of a new resonance in the χ(c1)γ final state is found with a statistical significance of 3.8σ. This state has a mass of 3823.1±1.8(stat)±0.7(syst) MeV/c(2), a value that is consistent with theoretical expectations for the previously unseen 1(3)D(2) cc[over ¯] meson. We find no other narrow resonance and set upper limits on the branching fractions of the X(3872)→χ(c1)γ and χ(c2)γ decays.

Study of e+ e- → π+ π- J/ψ and observation of a charged charmoniumlike state at Belle

The cross section for ee+ e- → π+ π- J/ψ between 3.8 and 5.5 GeV is measured with a 967  fb(-1) data sample collected by the Belle detector at or near the Υ(nS) (n = 1,2,…,5) resonances. The Y(4260) state is observed, and its resonance parameters are determined. In addition, an excess of π+ π- J/ψ production around 4 GeV is observed. This feature can be described by a Breit-Wigner parametrization with properties that are consistent with the Y(4008) state that was previously reported by Belle. In a study of Y(4260) → π+ π- J/ψ decays, a structure is observed in the M(π(±)J/ψ) mass spectrum with 5.2σ significance, with mass M = (3894.5 ± 6.6 ± 4.5)  MeV/c2 and width Γ = (63 ± 24 ± 26)  MeV/c2, where the errors are statistical and systematic, respectively. This structure can be interpreted as a new charged charmoniumlike state.

Search for an H-dibaryon with a mass near 2mΛ in Υ(1S) and Υ(2S) decays

We report the results of a high-statistics search for H dibaryon production in inclusive Υ(1S) and Υ(2S) decays. No indication of an H dibaryon with a mass near the M(H)=2m(Λ) threshold is seen in either the H→Λpπ(-) or ΛΛ decay channels and 90% confidence level branching-fraction upper limits are set that are between one and two orders of magnitude below the measured branching fractions for inclusive Υ(1S) and Υ(2S) decays to antideuterons. Since Υ(1S,2S) decays produce flavor-SU(3)-symmetric final states, these results put stringent constraints on H dibaryon properties. The results are based on analyses of 102 million Υ(1S) and 158 million Υ(2S) events collected with the Belle detector at the KEKB e(+)e(-) collider.

Clinical characteristics of patients with tuberculosis-destroyed lung

SETTING

Multicentre study.

OBJECTIVE

To define the clinical characteristics of patients with tuberculosis (TB) destroyed lung due to past TB.

DESIGN

We reviewed patients with TB-destroyed lung between May 2005 and June 2011.

RESULTS

A total of 595 patients from 21 hospitals were enrolled. The mean age was 65.63 ± 0.47 (mean ± standard error); 60.5% were male. The mean number of lobes involved was 2.59 ± 0.05. Pleural thickening was observed in 54.1% of the patients. Mean forced vital capacity (FVC), forced expiratory volume in 1 s (FEV(1)), FEV(1)/FVC, bronchodilator response and number of exacerbations per year were respectively 2.06 ± 0.03 l (61.26% ± 0.79), 1.16 ± 0.02 l (49.05% ± 0.84), 58.03% ± 0.70, 5.70% ± 0.34, and 0.40 ± 0.04. The number of lobes involved was significantly correlated with FVC and FEV(1), and with the number of exacerbations per year. Use of long-acting muscarinic antagonists or long-acting beta-2 agonists plus inhaled corticosteroids resulted in bronchodilatory effects. Multivariable regression analysis showed that age, initial FEV(1) (%) and number of exacerbations during follow-up were independent factors affecting change in FEV(1).

CONCLUSION

Decreased lung function with exacerbation, and progressive decline of FEV(1) were observed in patients with TB-destroyed lung.

Redundant nerve roots of cauda equina mimicking intradural disc herniation: a case report

Redundant Nerve Roots (RNRs) is an uncommon clinical condition characterized by a tortuous, serpentine, large and elongated nerve root of the cauda equina. To our knowledge, most cases of RNRs are associated with lumbar stenosis, and RNRs associated with lumbar disc herniation has not been reported until now. Here we present a rare case of unusual RNRs associated with lumbar disc herniation mimicking intradural disc herniation.

Evidence for B- → τ- ν(τ) with a hadronic tagging method using the full data sample of Belle

We measure the branching fraction of B- → τ- ν(τ) using the full Υ(4S) data sample containing 772×10(6) BB pairs collected with the Belle detector at the KEKB asymmetric-energy e+ e- collider. Events with BB pairs are tagged by reconstructing one of the B mesons decaying into hadronic final states, and B- → τ- ν(τ) candidates are detected in the recoil. We find evidence for B- → τ- ν(τ) with a significance of 3.0 standard deviations including systematic errors and measure a branching fraction B(B- → τ- ν(τ))=[0.72(-0.25)(+0.27)(stat)±0.11(syst)]×10(-4).

Factors affecting tobacco use among middle school students in Saudi Arabia

A rapid rise in the number of tobacco users in Saudi Arabia has occurred in the past decade, particularly among the youth. This study identified socio-cultural determinants of tobacco use and explored possible approaches to prevent adolescents' tobacco use in Saudi Arabia. A cross-sectional survey was administered using a self-administered questionnaire for collecting information on risk and protective factors for tobacco use among middle school students. School selection was stratified by region, gender, and type (public or private). Of 1,186 7-9th grade students, 1,019 questionnaires were analyzed. Risk factors affecting tobacco use included all important others' perceptions; mother, sister, friend, teacher and important person's tobacco use; pressure to use tobacco from brother, sister, friend and important persons; easy access to tobacco and frequent skipping of classes. Protective factors for tobacco use included family's perception; friend, teacher and important person's tobacco use; parents' help; support from family, friends, and teachers; accessibility to tobacco; school performance and family income, father's education, and district of residence. The findings of this study show clear gender differences in social influences and attitudes towards tobacco use. Religious beliefs and access to tobacco products were significantly associated with attitudes towards tobacco use and future intention of use. Developing and implementing effective gender specific school-based tobacco prevention programs, strict reinforcement of tobacco control policies, and a focus on the overall social context of tobacco use are crucial for developing successful long-term tobacco prevention programs for adolescents.

Angiographic results of indirect and combined bypass surgery for adult moyamoya disease

OBJECTIVE

The aim of this study was to compare the efficacy of indirect and combined bypass surgery for treatment of adult moyamoya disease (MMD). The definition of combined bypass surgery is a combination of superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis and indirect anastomosis. Development of collateral circulation after surgery was investigated.

METHODS

Forty three patients (58 hemispheres) with MMD were followed by cerebral angiography for at least six months after surgery, between May 2002 and July 2011. Indirect and combined revascularization surgeries were performed in 33 and 25 cases, respectively. Good outcome was defined as more than group B, in accordance with the method suggested by Matsushima.

RESULTS

Development of collateral circulation was not affected by sex (p = 0.493), clinical features (p = 0.206), or Suzuki stage (p = 0.428). Based on postoperative cerebral angiography, the combined bypass surgery group showed a better angiographic outcome, than the encephaloduroarteriomyosynangiosis (EDAMS) group (p = 0.100, odds ratio [OR] 4.107, 95% confidence interval [CI] 0.700 - 24.096). The combined bypass group showed a better response than the encephaloduroarteriogaleosynangiosis (EDAGS) group (p = 0.088, OR 4.600, 95% CI 0.721 - 29.332). Similar responses were observed for EDAGS and EDAMS (p = 0.886, OR 1.120, 95% CI 0.239 - 5.251). The combined bypass group showed a better response than the indirect group (p = 0.064, OR 4.313, 95% CI 0.840 - 22.130).

CONCLUSION

Results of this study demonstrate that combined bypass results in better revascularization on angiographic evaluation in adult MMD. Therefore, among surgical procedures, combined bypass is a choice that can be recommended.

Appearance and dynamics of helical flux tubes under electron cyclotron resonance heating in the core of KSTAR plasmas

Dual (or sometimes multiple) flux tubes (DFTs) have been observed in the core of sawtoothing KSTAR tokamak plasmas with electron cyclotron resonance heating. The time evolution of the flux tubes visualized by a 2D electron cyclotron emission imaging diagnostic typically consists of four distinctive phases: (1) growth of one flux tube out of multiple small flux tubes during the initial buildup period following a sawtooth crash, resulting in a single dominant flux tube along the m/n=1/1 helical magnetic field lines, (2) sudden rapid growth of another flux tube via a fast heat transfer from the first one, resulting in approximately identical DFTs, (3) coalescence of the two flux tubes into a single m/n=1/1 flux tube resembling the internal kink mode in the normal sawteeth, which is explained by a model of two current-carrying wires confined on a flux surface, and (4) fast localized crash of the merged flux tube similar to the standard sawtooth crash. The dynamics of the DFTs implies that the internal kink mode is not a unique prerequisite to the sawtooth crash, providing a new insight on the control of the sawtooth.

Utility of Basal luteinizing hormone levels for detecting central precocious puberty in girls

The hallmark of puberty is the progressive increase in gonadotropin-releasing hormone (GnRH) activity, reflected by an increase in the circulating concentration of luteinizing hormone (LH). The GnRH stimulation test is widely used in the evaluation of precocious puberty. The aim of our study was to assess the diagnostic utility of basal LH for the diagnosis of central precocious puberty (CPP) in girls. A total of 803 girls were referred to Ajou University Hospital for evaluation of precocious puberty between 2008 and 2011. All subjects underwent GnRH-stimulation tests as part of their evaluation. Serum LH and follicle stimulating hormone (FSH) were measured by immunoradiometric assay before and after the GnRH injection. Of the 803 subjects, 505 (62.9%) were included in the pubertal response group and 298 (37.1%) were in the prepubertal response group. Basal LH level was identified as a significant predictor for CPP. Based on the ROC curve, the optimal cut off point of basal LH related to 'pubertal response' was 1.1 IU/l, which was associated with 69.1% sensitivity and 50.5% specificity, with an area under the ROC curve of 0.620 (95% CI, 0.581-0.660). It is concluded that a single basal LH measurement can be used as a screening test to identify girls with CPP and to determine who should undergo GnRH stimulation test.

Design of the reflective optics for Tore Supra ECEI system

A 2D electron cyclotron emission (ECE) imaging system for Tore Supra is under design for studying the MHD physics of the magnetically confined plasma such as sawteeth, tearing modes, and turbulent fluctuations. Complex beam path due to the tight access in Tore Supra led to the design of reflective optics made of 6 or more large cylindrical∕flat mirrors. The total path length of the ECE beam is about 11 m, including almost 4 m inside the vacuum vessel. The imaging property of the optics has been estimated using the Gaussian beam simulation and ray transfer analysis. The possible setups for the optical alignment of the diagnostic and the operation scenarios with single- or dual-array measurement system are discussed.

Evidence for CP violation in the decay D+ → K(S)(0)π+

We observe evidence for CP violation in the decay D+ → K(S)(0)π+ using a data sample with an integrated luminosity of 977  fb(-1) collected by the Belle detector at the KEKB e+ e- asymmetric-energy collider. The CP asymmetry in the decay is measured to be (-0.363±0.094±0.067)%, which is 3.2 standard deviations away from zero, and is consistent with the expected CP violation due to the neutral kaon in the final state.

Patterns of initial disease recurrence after resection of biliary tract cancer

OBJECTIVES

This study aimed to provide further insights into the indications for adjuvant therapeutic strategies via analysis of the sites of initial recurrence after resection of gallbladder cancer (GBC) and intrahepatic (IHC) and extrahepatic cholangiocarcinoma (EHC).

METHODS

Patients with biliary tract cancer who underwent potentially curative resection were identified from the database. Sites of initial disease recurrence were categorized as locoregional or distant.

RESULTS

Between March 2001 and April 2009, 231 patients underwent curative resection. Initial GBC and IHC recurrence involving a distant site occurred in 70.8 and 86.8% patients, respectively, compared to 56.9% patients with EHC (p = 0.002). The median time to disease recurrence (TTR) was shorter among the GBC and IHC groups compared with that in EHC patients (6.3 and 6.7 vs. 13.1 months, respectively; p = 0.003). Moreover, median times to distant recurrence in GBC and IHC groups were shorter than that in EHC (5.8 and 6.5 vs. 14.1 months, respectively; p = 0.002).

CONCLUSIONS

After resection, recurrent GBC and IHC are more likely to involve a distant site and are associated with significantly shorter TTR than recurrent EHC. These findings suggest that an adjuvant therapeutic strategy targeting distant disease is likely to have a significant impact on the overall management of GBC and IHC.

Development of a novel PCR assay based on the 16S-23S rRNA internal transcribed spacer region for the detection of Lactococcus garvieae

Lactococcus garvieae is recognized as an emerging pathogen in fish. Several PCR-based methods have been developed for the detection and identification of L. garvieae; however, the sensitivity of these methods is still in question regarding the discrimination of this organism from other closely related species. Two primers, ITSLg30F and ITSLg319R, were designed from the sequence in the 16S-23S internal transcribed spacer (ITS) region and used for the specific detection of L. garvieae. L. garvieae strains including fish isolates were positive by this method. In contrast, previously developed PCR methods showed false-positive results with non-L. garvieae species. Our results indicate that a PCR method using the newly designed ITS primer set provides a sensitive and efficient tool for the detection of L. garvieae in fish and aquaculture environments.

HbA1c and glucose intolerance in obese children and adolescents

AIMS

Childhood obesity is associated with an increased likelihood for having impaired glucose tolerance, dyslipidaemia and diabetes. The aim of the study was to evaluate HbA(1c) as a screening test for impaired glucose tolerance in obese children and adolescents and identify the optimal HbA(1c) threshold.

METHODS

We studied 126 obese and overweight children (BMI > 85 th percentile for age and gender) 4-17 years of age referred to the endocrine clinic at Ajou University Hospital in Korea. All subjects underwent HbA(1c) and oral glucose tolerance test.

RESULTS

Thirty-four patients (27%) out of 126 had impaired glucose tolerance. Silent diabetes was diagnosed in 10 adolescents (7.9%). Based on the receiver operating characteristic curve, the optimal cut point of HbA(1c) related to impaired glucose tolerance diagnosed by oral glucose tolerance test was 40 mmol/mol (5.8%), which was associated with a 64.7% sensitivity and 61.6% specificity, with an area under the receiver operating characteristic curve of 0.651 (95% CI 0.529-0.772).

CONCLUSIONS

Obesity is associated with an increased risk of impaired glucose tolerance. An HbA(1c) value of 40 mmol/mol (5.8%) should be used as a screening tool to identify children and adolescents with impaired glucose tolerance.