Use of group IIB metal ions as charge carriers for collision-induced dissociation of glycopeptide and glycan.

RATIONALE: Dissociation of biomolecules by tandem mass spectrometry (MS/MS) generates a variety of fragment ions which provide useful information for the structural characterization of biomolecules. Different fragmentation strategies result in different mass spectra for the same molecule and thus provide distinct features. Charge carriers play important roles in determining the dissociation pathways of the target precursor ions. The use of various transition metals ions as charge carriers of glycopeptide and glycan might provide additional structural information and needs to be investigated. METHODS: A 9.4 T SolariX FTICR mass spectrometer was used for collision-induced dissociation (CID) of glycopeptide and glycan. Group IIB metal ions, including Zn2+ , Cd2+ and Hg2+ , were used as charge carriers. Glycopeptide NLTK-M5 G2 and glycan G1F were used as the model systems. RESULTS: For Zn2+ - and Cd2+ -adducted species, cross-ring cleavages, glycosidic cleavages and cleavages along the peptide backbone could be obtained. There is a high degree of similarity in their CID spectra with that of Mg2+ ion-adducted glycopeptide species. For Hg2+ -adducted species, only glycosidic cleavages were observed in high abundance. The formation of doubly-charged ions (M2+ ) and a series of [f-H]+ fragments indicated unique dissociation pathways for Hg2+ -adducted glycopeptide. CONCLUSIONS: Zn2+ and Cd2+ -adducted glycopeptide species produced similar dissociation CID spectra, whereas Hg2+ -adducted species produced significantly different CID spectra. Similar CID dissociation features were also observed for Group IIB metal ions adducted glycan species. These results demonstrated that different metal ions might be used to tune the dissociation behaviors of glycopeptides and glycans.

Search for Light Weakly-Interacting-Massive-Particle Dark Matter by Annual Modulation Analysis with a Point-Contact Germanium Detector at the China Jinping Underground Laboratory.

We present results on light weakly interacting massive particle (WIMP) searches with annual modulation (AM) analysis on data from a 1-kg mass p-type point-contact germanium detector of the CDEX-1B experiment at the China Jinping Underground Laboratory. Datasets with a total live time of 3.2 yr within a 4.2-yr span are analyzed with analysis threshold of 250 eVee. Limits on WIMP-nucleus (χ-N) spin-independent cross sections as function of WIMP mass (m_{χ}) at 90% confidence level (C.L.) are derived using the dark matter halo model. Within the context of the standard halo model, the 90% C.L. allowed regions implied by the DAMA/LIBRA and CoGeNT AM-based analysis are excluded at >99.99% and 98% C.L., respectively. These results correspond to the best sensitivity at m_{χ}<6 GeV/c^{2} among WIMP AM measurements to date.

Constraints on Spin-Independent Nucleus Scattering with sub-GeV Weakly Interacting Massive Particle Dark Matter from the CDEX-1B Experiment at the China Jinping Underground Laboratory.

We report results on the searches of weakly interacting massive particles (WIMPs) with sub-GeV masses (m_{χ}) via WIMP-nucleus spin-independent scattering with Migdal effect incorporated. Analysis on time-integrated (TI) and annual modulation (AM) effects on CDEX-1B data are performed, with 737.1 kg day exposure and 160 eVee threshold for TI analysis, and 1107.5 kg day exposure and 250 eVee threshold for AM analysis. The sensitive windows in m_{χ} are expanded by an order of magnitude to lower DM masses with Migdal effect incorporated. New limits on σ_{χN}^{SI} at 90% confidence level are derived as 2×10^{-32}∼7×10^{-35} cm^{2} for TI analysis at m_{χ}∼50-180 MeV/c^{2}, and 3×10^{-32}∼9×10^{-38} cm^{2} for AM analysis at m_{χ}∼75 MeV/c^{2}-3.0 GeV/c^{2}.

Limits on Light Weakly Interacting Massive Particles from the First 102.8 kg×day Data of the CDEX-10 Experiment.

We report the first results of a light weakly interacting massive particles (WIMPs) search from the CDEX-10 experiment with a 10 kg germanium detector array immersed in liquid nitrogen at the China Jinping Underground Laboratory with a physics data size of 102.8 kg day. At an analysis threshold of 160 eVee, improved limits of 8×10^{-42} and 3×10^{-36} cm^{2} at a 90% confidence level on spin-independent and spin-dependent WIMP-nucleon cross sections, respectively, at a WIMP mass (m_{χ}) of 5 GeV/c^{2} are achieved. The lower reach of m_{χ} is extended to 2 GeV/c^{2}.

Pulmonary hypertension and echocardiogram parameters in obstructive sleep apnea.

Obstructive sleep apnea (OSA) is a growing health hazard in the United States and worldwide. OSA is now recognized as a disorder with systemic manifestations and its association with obesity and adverse cardiovascular consequences. There is increasing evidence that OSA may be associated with systemic hypertension and an increased incidence of stroke, heart failure, myocardial infarction, and arrhythmias. Less information is available about the association between OSA and pulmonary hypertension (PH). We therefore conduct this study to look at the prevalence of the pulmonary hypertension in obstructive sleep apnea patient and to identify risk factors leading to pulmonary hypertension among OSA patient. We studied and analyzed all OSA patient confirmed by polysomnograph in the year 2015. Twenty-five patients with OSA were included in this study with prevalence of pulmonary hypertension of 16%. Univariate analysis of various factors revealed a statistically significant association between having the lowest SpO2 of <70% and pulmonary hypertension (p = 0.016). There were no statistically significant associations between age, gender, smoking status, hypertension, body mass index (BMI), or apnea-hypopnea index (AHI) with occurrence of pulmonary hypertension. AHI is not a good predictor for pulmonary hypertension. The real value of using AHI to predict the health risk of OSA is doubtful. We recommend routine echocardiogram among OSA patient. The objective information in the echocardiogram provides evidence for counseling of patient with disease of OSA and hence hopefully can improve compliance of patient to treatment especially usage of CPAP.

An update of the Hong Kong Epilepsy Guideline: consensus statement on the use of antiepileptic drugs in Hong Kong.

OBJECTIVE: New information about antiepileptic drugs has arisen since the publication of the Hong Kong Epilepsy Guideline in 2009. This article set out to fill the knowledge gap between 2007 and 2016 on the use of antiepileptic drugs in Hong Kong. PARTICIPANTS: Between May 2014 and April 2016, four consensus meetings were held in Hong Kong, where a group comprising 15 professionals (neurologists, paediatricians, neurosurgeons, radiologists, and clinical psychologists) from both public and private sectors aimed to review the best available evidence and update all practising physicians on a range of clinical issues including drug-related matters. All participants were council members of The Hong Kong Epilepsy Society. EVIDENCE: A literature review of the clinical use of antiepileptic drugs as monotherapy suggested Level A evidence for levetiracetam and Level B evidence for lacosamide. No change in the level of evidence was found for oxcarbazepine (Level A evidence) or pregabalin (undesignated), and no evidence was found for perampanel. A literature review on the clinical use of antiepileptic drugs as adjunctive therapy suggested Level A evidence for both lacosamide and perampanel. No change to the level of evidence was found for levetiracetam (Level A evidence), oxcarbazepine (Level A evidence), or pregabalin (Level A evidence). A literature search on the use of generic antiepileptic drugs suggested Level A evidence for the use of lamotrigine in generic substitution. CONSENSUS PROCESS: Three lead authors of the Subcommittee drafted the manuscript that consisted of two parts-part A: evidence on new antiepileptic drugs, and part B: generic drugs. The recommendations on monotherapy/adjunctive therapy were presented during the meetings. The pros and cons for our health care system of generic substitution were discussed. The recommendations represent the 'general consensus' of the participants in keeping with the evidence found in the literature. CONCLUSIONS: Recommendations for the use of levetiracetam, lacosamide, oxcarbazepine, pregabalin, and perampanel were made. The consensus statements may provide a reference to physicians in their daily practice. Controversy exists over the use of generic products among patients who are currently taking brand medications. In this regard, approvals from prescriber and patient are pivotal. Good communication between doctors and patients is essential, as well as enlisting the assistance of doctors, nurses, and pharmacists, therapeutic blood monitoring if available, and the option of brand antiepileptic drug as a self-financed item. The physical appearance of generic drugs should be considered as it may hamper drug compliance. Support from medical services is recommended. In the longer term, the benefit of flexibility and the options to have a balance between the generic and brand drug market may need to be addressed by institutions and regulatory bodies.

Primary ventriculoperitoneal shunting outcomes: a multicentre clinical audit for shunt infection and its risk factors.

OBJECTIVES: To determine the frequency of primary ventriculoperitoneal shunt infection among patients treated at neurosurgical centres of the Hospital Authority and to identify underlying risk factors. METHODS: This multicentre historical cohort study included consecutive patients who underwent primary ventriculoperitoneal shunting at a Hospital Authority neurosurgery centre from 1 January 2009 to 31 December 2011. The primary endpoint was shunt infection, defined as: (1) the presence of cerebrospinal fluid or shunt hardware culture that yielded the pathogenic micro-organism with associated compatible symptoms and signs of central nervous system infection or shunt malfunction; or (2) surgical incision site infection requiring shunt reinsertion (even in the absence of positive culture); or (3) intraperitoneal pseudocyst formation (even in the absence of positive culture). Secondary endpoints were shunt malfunction, defined as unsatisfactory cerebrospinal fluid drainage that required shunt reinsertion, and 30-day mortality. RESULTS: A primary ventriculoperitoneal shunt was inserted in 538 patients during the study period. The mean age of patients was 48 years (range, 13-88 years) with a male-to-female ratio of 1:1. Aneurysmal subarachnoid haemorrhage was the most common aetiology (n=169, 31%) followed by intracranial tumour (n=164, 30%), central nervous system infection (n=42, 8%), and traumatic brain injury (n=27, 5%). The mean operating time was 75 (standard deviation, 29) minutes. Shunt reinsertion and infection rates were 16% (n=87) and 7% (n=36), respectively. The most common cause for shunt reinsertion was malfunction followed by shunt infection. Independent predictors for shunt infection were: traumatic brain injury (adjusted odds ratio=6.2; 95% confidence interval, 2.3-16.8), emergency shunting (2.3; 1.0-5.1), and prophylactic vancomycin as the sole antibiotic (3.4; 1.1-11.0). The 30-day all-cause mortality was 6% and none were directly procedure-related. CONCLUSIONS: This is the first Hong Kong territory-wide review of infection in primary ventriculoperitoneal shunts. Although the ventriculoperitoneal shunt infection rate met international standards, there are areas of improvement such as vancomycin administration and the avoidance of scheduling the procedure as an emergency.

Update to the Hong Kong Epilepsy Guideline: evidence-based recommendations for clinical management of women with epilepsy throughout the reproductive cycle.

Since the publication of the Hong Kong Epilepsy Guideline in 2009, there has been significant progress in antiepileptic drug development. New AEDs have emerged, and data about their uses have been published. Women require special attention in epilepsy care. Drug teratogenicity, pregnancy, breastfeeding, contraception, reproduction technology, menopause, and catamenial epilepsy are major topics. Antiepileptic drugs should be chosen individually for patients who are pregnant or may become pregnant with consideration of their teratogenicity and seizure control properties. Folate is commonly prescribed for women of childbearing age who are taking antiepileptic drugs. Spontaneous vaginal delivery and breastfeeding are not contra-indicated in most cases but need to be considered individually based on the patient's medical condition and wishes. Serum drug level monitoring of certain antiepileptic drugs during pregnancy and puerperium can guide dosage adjustment. For catamenial epilepsy, intermittent benzodiazepines such as clobazam during the susceptible phase of the menstrual cycle could be a treatment option.

Limits on spin-independent couplings of WIMP dark matter with a p-type point-contact germanium detector.

We report new limits on a spin-independent weakly interacting massive particle (WIMP)-nucleon interaction cross section using 39.5 kg days of data taken with a p-type point-contact germanium detector of 840 g fiducial mass at the Kuo-Sheng Reactor Neutrino Laboratory. Crucial to this study is the understanding of the selection procedures and, in particular, the bulk-surface events differentiation at the sub-keV range. The signal-retaining and background-rejecting efficiencies were measured with calibration gamma sources and a novel n-type point-contact germanium detector. Part of the parameter space in the cross section versus WIMP-mass implied by various experiments is probed and excluded.

CaptiveSpray Differential Ion Mobility Spectrometry Device with Enhanced Ion Transmission and Improved Resolving Power.

A performance enhanced CaptiveSpray differential ion mobility device was designed and constructed by incorporating a circular channel and a gas flow homogenizing channel (GFHC) between the CaptiveSpray ion source and planar differential ion mobility spectrometry (DMS). The GFHC was used to reduce gas flow heterogeneity prior to the entrance of the DMS device. The optimal flared entrance greatly reduces gas flow velocity at the inlet region owing to its relatively large gas inlet interface, which assists in reducing disparities between the minimum and maximum gas velocity along the x-axis. The circular electrode was machined with channels along the x- and y-axis for the passage of auxiliary gas and was applied with a potential to focus the incoming ions from the CaptiveSpray source into the DMS channel. Using reserpine as a reference standard, substantial signal enhancement was achieved with a concomitant reduction of the peak width in the ionogram.

Weather inference and daily demand for emergency ambulance services.

AIM: To examine weather effects on the daily demand for ambulance services in Hong Kong. METHODS: Over 6 million cases of emergency attendance from May 2006 through April 2009 (3 years) were obtained from the Hospital Authority in Hong Kong. These cases were further stratified by age, triage levels, hospital admission status, comprehensive social security assistance (CSSA) recipients and gender. The stratification was used to correlate against weather factors to assess the dependency of these variables and their effects on the daily number of ambulance calls. Adjusted-R(2) values obtained from the regression analysis were used as a measure for evaluating predictability. RESULTS: The adjusted-R(2) of emergency cases by age groups showed proportional correlation with weather factors, which was more significant in older patients (0.76, p<0.01) than young patients (0.10, p<0.05). Furthermore, patients with more severe conditions were shown to have a higher adjusted-R(2) (0.63, p<0.05 for critical as opposed to 0 for non-urgent patients). Weather effects were also found more significant in women (0.50, p<0.01) and CSSA recipients (0.54, p<0.01) when compared against their corresponding reference groups (respectively men at 0.46, p<0.01 and non-CSSA recipients at 0.45, p<0.01). Moreover, average temperature appeared to be a major weather effect. CONCLUSIONS: The presence of strong weather effects among different target groups indicates possibility for the development of a short-term forecast system of daily ambulance demand using weather variables. The availability of such a forecast system would render more effective deployment of the ambulance services to meet the unexpected increase in service demands.

Tandem Mass Spectrometry for Structural Characterization of Doubly-Charged N-Linked Glycopeptides.

Three dissociation methods, including collision-induced dissociation (CID), electron capture dissociation (ECD), and electronic excitation dissociation (EED), were systematically compared for structural characterization of doubly charged glycopeptide. CID produced distinctively different tandem mass spectra for glycopeptide adducted with different charge carriers. Protonated species produced mainly glycosidic cleavages in high abundance. CID of magnesiated glycopeptide formed more cross-ring cleavages, whereas doubly sodiated species produced cleavages at both glycan and peptide moieties. The effect of charge carriers on the fragmentation in ECD and EED was lower than that in CID. ECD produced mainly peptide backbone cleavages but limited cleavages at the glycan moiety, whereas EED of glycopeptide resulted in extensive fragmentation throughout the molecular ion regardless of the charge carriers. Magnesiated species gave, however, more cross-ring cleavages than other charge carriers did. These results demonstrated that EED of magnesiated species could be used as a one-step dissociation method for comprehensive structural analysis of glycopeptides.

Dissociation of Mannose-Rich Glycans Using Collision-Based and Electron-Based Ion Activation Methods.

Three dissociation methods, including collision-induced dissociation (CID), electron capture dissociation (ECD), and electronic excitation dissociation (EED), were evaluated for the dissociation of doubly charged glycans using sodium or magnesium ions as charge carriers. CID produced mainly glycosidic cleavages, although more cross-ring fragment ions could be obtained at higher intensities when magnesium ions were used as charge carriers [M + Mg]2+. The 0,2A3, 0,3A3, and 0,4A3 ions provided structural information on the 3 → 1 and 6 → 1 linkages of the mannoses. Some internal fragment ions, such as 2,4A5_Y3ß, were also produced in high abundance, thus providing additional information on the glycan structure. ECD produced limited fragments compared to other dissociation methods when either of the metal ions were used as charge carriers. Cross-ring fragments were obtained in relatively high abundance, with the charge mainly retained on the nonreducing end. EED produced extensive glycosidic and cross-ring cleavages when either metal charge carrier was used. A higher fragmentation efficiency was achieved and more structural-specific fragments were produced when Na+ was used as the charge carrier. Of the 31 possible cross-ring cleavages, including 0,2-, 0,4-, 1,5-, 2,4-, and 3,5-cleavages, 25 were found, thus providing extensive linkage information. A wide range of fragment ions could be obtained in all dissociation methods when Mg2+ was used as the charge carrier. Two specific analytical approaches were found to produce extensively structural-specific information on the glycans studied, namely CID of magnesiated glycans and EED of sodiated glycans. These two methods were selected to further analyze the larger mannose-rich glycans Man6GlcNAc2 and Man8GlcNAc2 and generated extensive structural information.

Intracranial electroencephalogram to evaluate refractory temporal and frontal lobe epilepsy.

OBJECTIVE: We undertook a collaborative study in a multidisciplinary team to channel refractory epilepsy patients to test a hypothesis about placement of intracranial electroencephalography arrays. DESIGN: This was a descriptive case series. Prospective non-invasive presurgical evaluations were based on clinical semiology, magnetic resonance imaging, video-electroencephalography findings and neuropsychological assessments. If the results were discordant, a hypothesis was generated using individualised combinations of positron emission tomography, single-photon emission computed tomography, functional magnetic resonance imaging and Wada tests. The indications for intracranial electroencephalography were: (a) focal magnetic resonance imaging, ictal/interictal scalp electroencephalography with variable results (group A); (b) multi-focal magnetic resonance imaging, focal/multi-focal ictal scalp electroencephalography (group B); (c) non-lesional magnetic resonance imaging, focal/multi-focal ictal scalp electroencephalography (group C). We evaluated whether the seizure-onset zones and eloquent areas were delineated, surgical outcomes (if operated on), and pathology results. SETTING: A tertiary referral centre for neurology in Hong Kong. PATIENTS: A total of 105 refractory epilepsy patients completed non-invasive presurgical evaluations over the period 2007 to 2009. Thirty-two patients were eligible for direct resective surgery, and another 25 patients had a testing hypothesis formulated. Of these 25 patients, 10 were eligible for intracranial electroencephalography based on technical/financial considerations. RESULTS: All 10 patients (group A=2, group B=4, group C=4) had their epileptogenic zones defined. Six patients underwent functional mapping, all of whom had their eloquent areas defined. Seven of the 10 patients underwent resective surgery; four of them achieved Engel class I/II outcomes. The dichotomised outcomes were 100% (group A), 50% (group B), and 33% (group C) achieving Engel class I/II. Two patients had asymptomatic subdural haematoma. There was no intracranial infection or operative mortality. In five (71%) of seven of the patients, a histological diagnosis was established. CONCLUSION: Proper deployment of intracranial electroencephalography is useful in the presurgical evaluation of patients with refractory epilepsy. This modality of management is potentially of benefit for patients with refractory epilepsy, but is underutilised locally.

Synergistic effects of dehydroepiandrosterone and fluoxetine on proliferation of progenitor cells in the dentate gyrus of the adult male rat.

The 5-HT re-uptake inhibitor (SSRI) fluoxetine and the adrenal hormone dehydroepiandrosterone (DHEA) both increase the proliferation of progenitor cells in the adult hippocampus and also have antidepressant activity. This paper explores the combined ability of fluoxetine and DHEA to affect this process in the dentate gyrus of adult rats. We show that DHEA can render an otherwise ineffective dose of fluoxetine (2.5 mg/kg) able to increase progenitor cell proliferation to the same extent as doses four times higher (10 mg/kg). This synergistic action does not appear to be mediated by alterations in brain-derived neurotrophic factor (BDNF) gene expression; or by TrkB, mineralocorticoid, glucocorticoid, or 5-HT (5HT1A) receptor expression in the dentate gyrus; or by altered levels of plasma corticosterone. In a second experiment, the synergism between DHEA and fluoxetine was replicated. Furthermore, flattening the diurnal rhythm of plasma corticosterone by implanting additional corticosterone pellets s.c. prevented the effect of fluoxetine on progenitor cell division. This was not overcome by simultaneous treatment with DHEA, despite the latter's reported anti-glucocorticoid actions. The cellular mechanism for the potentiating action of DHEA on the pro- proliferative effects of fluoxetine in the adult hippocampus remains to be revealed. Since altered neurogenesis has been linked to the onset or recovery from depression, one consequence of these results is to suggest DHEA as a useful adjunct therapy for depression.

Rapid Differentiation of Asian and American Ginseng by Differential Ion Mobility Spectrometry-Tandem Mass Spectrometry Using Stepwise Modulation of Gas Modifier Concentration.

This study reports a rapid and robust method for the differentiation of Asian and American ginseng samples based on differential ion mobility spectrometry-tandem mass spectrometry (DMS-MS/MS). Groups of bioactive ginsenoside/pseudo-ginsenoside isomers, including Rf/Rg1/F11, Rb2/Rb3/Rc, and Rd/Re, in the ginseng extracts were sequentially separated using DMS with stepwise changes in the gas modifier concentration prior to MS analysis. The identities of the spatially separated ginsenoside/pseudo-ginsenoside isomers were confirmed by their characteristic compensation voltages at specific modifier loading and MS/MS product ions. As expected, Asian ginseng samples contained some Rf and an insignificant amount of F11, whereas American ginseng samples had a high level of F11 but no Rf. The origin of the whole and sliced ginseng could further be confirmed using the quantitative ratios of three sets of ginsenoside markers, namely, Rg1/Re, Rb1/Rg1, and Rb2/Rc. Based on our results, new benchmark ratios of Rg1/Re < 0.15, Rb1/Rg1 > 2.15, and Rb2/Rc < 0.26 were proposed for American ginseng (as opposed to Asian ginseng).

Performance Enhancements in Differential Ion Mobility Spectrometry-Mass Spectrometry (DMS-MS) by Using a Modified CaptiveSpray Source.

Differential ion mobility spectrometry (DMS) spatially separates ions in the gas phase using the mobility differences of the ions under applied low and high electric fields. The use of DMS as an ion filter (or ion selector) prior to mass spectrometry analysis has been compromised by the limited ion transmission efficiency. This paper reports enhancement of the DMS-MS sensitivity and signal stability using a modified CaptiveSpray™ source. In terms of the ion sampling and transmission efficiency, the modified CaptiveSpray source swept ~ 89% of the ions generated by the tapered capillary through the DMS device (compared to ~ 10% with a conventional microspray source). The signal fluctuation improved from 11.7% (relative standard deviation, RSD) with microspray DMS-MS to 3.6% using CaptiveSpray-DMS-MS. Coupling of LC to DMS-MS via the modified CaptiveSpray source was simple and robust. Using DMS as a noise-filtering device, LC-DMS-MS performed better than conventional LC-MS for analyzing a BSA digest standard. Although LC-DMS-MS had a lower sequence coverage (55%), a higher Mascot score (283) was obtained compared to those of LC-MS (sequence coverage 65%; Mascot score 192) under the same elution conditions. The improvement in the confidence of the search result was attributed to the preferential elimination of noise ions. Graphical Abstract ᅟ.

A meta-analysis of overall effects of weight loss interventions delivered via mobile phones and effect size differences according to delivery mode, personal contact, and intervention intensity and duration.

Weight loss interventions are delivered through various mediums including, increasingly, mobile phones. This systematic review and meta-analysis assesses whether interventions delivered via mobile phones reduce body weight and which intervention characteristics are associated with efficacy. The study included randomised controlled trials assessing the efficacy of weight loss interventions delivered via mobile phones. A meta-analysis to test intervention efficacy was performed, and subgroup analyses were conducted to determine whether interventions' delivery mode(s), inclusion of personal contact, duration and interaction frequency improve efficacy. Pooled body weight reduction (d = -0.23; 95% confidence interval = -0.38, -0.08) was significant. Interventions delivered via other modes in addition to the mobile phone were associated with weight reduction. Personal contact and more frequent interactions in interventions were also associated with greater weight reduction. In conclusion, the current body of evidence shows that interventions delivered via mobile phones produce a modest reduction in body weight when combined with other delivery modes. Delivering interventions with frequent and personal interactions may in particular benefit weight loss results.

Lateral thyroid cartilage thyrotomy approach to an embedded paraglottic fishbone.

Fishbones are of particular interest to otolaryngologists. Most fishbones can be removed transorally or via endoscopic guidance. Transcervical neck exploration is occasionally necessary, especially in cases of an embedded foreign body. Computed tomography is the most sensitive and specific imaging modality for identifying embedded fishbones. To our knowledge, this is the first reported case of a laryngeal foreign body embedded in the paraglottic space that was removed using an open approach via a lateral thyroid cartilage window.

Study of inactive layer uniformity and charge collection efficiency of a p-type point-contact germanium detector.

The characteristics of the surface inactive layer of a 1-kg-mass p-type point-contact germanium detector were studied. The thickness of the inactive layer and its uniformity on the top and lateral surfaces were measured. A charge collection efficiency function was developed according to the Monte Carlo simulation to describe the charge collection capacity along the depth within this inactive layer. In the energy range below 18keV, the surface, bulk, and total spectra of 57Co, 133Ba, 137Cs, and 60Co from simulations based on the charge collection efficiency function were well consistent with those from experiments.