Evaluation of urea breath test as a diagnostic tool for Helicobacter pylori infection in adult dyspeptic patients

In this editorial,we discuss the article in the World Journal of Gastroenterology.The article conducts a meta-analysis of the diagnostic accuracy of the urea breath test(UBT),a non-invasive method for detecting Helicobacter pylori(H.pylori)infection in humans.It is based on radionuclide-labeled urea.Various methods,both invasive and non-invasive,are available for diagnosing H.pylori infection,inclu-ding endoscopy with biopsy,serology for immunoglobulin titers,stool antigen analysis,and UBT.Several guidelines recommend UBTs as the primary choice for diagnosing H.pylori infection and for reexamining after eradication therapy.It is used to be the first choice non-invasive test due to their high accuracy,specificity,rapid results,and simplicity.Moreover,its performance remains unaffected by the distribution of H.pylori in the stomach,allowing a high flow of patients to be tested.Despite its widespread use,the performance characteristics of UBT have been inconsistently described and remain incompletely defined.There are two UBTs available with Food and Drug Administration approval:The 13C and 14C tests.Both tests are affordable and can provide real-time results.Physicians may prefer the 13C test because it is non-radioactive,compared to 14C which uses a radioactive isotope,especially in young children and pregnant women.Although there was heterogeneity among the studies regarding the diagnostic accuracy of both UBTs,13C-UBT consistently outperforms the 14C-UBT.This makes the 13C-UBT the preferred diagnostic approach.Furthermore,the provided findings of the meta-analysis emphasize the significance of precise considerations when choosing urea dosage,assessment timing,and measurement techniques for both the 13C-UBT and 14C-UBT,to enhance diagnostic precision.

Urea breath test for Helicobacter pylori infection in adult dyspeptic patients: A meta-analysis of diagnostic test accuracy

BACKGROUND Helicobacter pylori(H.pylori)infection has been well-established as a significant risk factor for several gastrointestinal disorders.The urea breath test(UBT)has emerged as a leading non-invasive method for detecting H.pylori.Despite numerous studies confirming its substantial accuracy,the reliability of UBT results is often compromised by inherent limitations.These findings underscore the need for a rigorous statistical synthesis to clarify and reconcile the diagnostic accuracy of the UBT for the diagnosis of H.pylori infection.AIM To determine and compare the diagnostic accuracy of 13C-UBT and 14C-UBT for H.pylori infection in adult patients with dyspepsia.METHODS We conducted an independent search of the PubMed/MEDLINE,EMBASE,and Cochrane Central databases until April 2022.Our search included diagnostic accuracy studies that evaluated at least one of the index tests(^(13)C-UBT or ^(14)C-UBT)against a reference standard.We used the QUADAS-2 tool to assess the methodo-logical quality of the studies.We utilized the bivariate random-effects model to calculate sensitivity,specificity,positive and negative test likelihood ratios(LR+and LR-),as well as the diagnostic odds ratio(DOR),and their 95%confidence intervals.We conducted subgroup analyses based on urea dosing,time after urea administration,and assessment technique.To investigate a possible threshold effect,we conducted Spearman correlation analysis,and we generated summary receiver operating characteristic(SROC)curves to assess heterogeneity.Finally,we visually inspected a funnel plot and used Egger’s test to evaluate publication bias.endorsing both as reliable diagnostic tools in clinical practice.CONCLUSION In summary,our study has demonstrated that ^(13)C-UBT has been found to outperform the ^(14)C-UBT,making it the preferred diagnostic approach.Additionally,our results emphasize the significance of carefully considering urea dosage,assessment timing,and measurement techniques for both tests to enhance diagnostic precision.Nevertheless,it is crucial for researchers and clinicians to evaluate the strengths and limitations of our findings before implementing them in practice.

Advancements in breath-based diagnostics for pancreatic cancer:Current insights and future perspectives

Recent decades have seen a concerning surge in carcinogenic diseases,with cancer cases and deaths on the rise globally.Conventional diagnostic methods are often invasive and time-consuming,highlighting the need for fast,accurate,and painless alternatives.Non-invasive exhaled breath analysis emerges as a promising solution,with over 200 volatile organic compounds(VOCs)detected in exhaled air,showing potential as biomarkers for various diseases,including cancer.Despite the lack of standardized methodologies,advancements in analytical instruments have expanded detection capabilities,reaching 3500 VOCs.Studies have identified specific VOC patterns associated with different cancers,offering hope for non-invasive diagnosis.Techniques such as gas chromatography-mass spectrometry and electronic noses show promise in distinguishing between healthy individuals and cancer patients.However,further research and standardization are needed to realize the full clinical potential of breath-based diagnostics,particularly in the early detection of challenging cancers like pancreatic cancer.

Identification of breath volatile organic compounds to distinguish pancreatic adenocarcinoma,pancreatic cystic neoplasm,and patients without pancreatic lesions

BACKGROUND Volatile organic compounds(VOCs)are a promising potential biomarker that may be able to identify the presence of cancers.AIM To identify exhaled breath VOCs that distinguish pancreatic ductal adenocar-cinoma(PDAC)from intraductal papillary mucinous neoplasm(IPMN)and healthy volunteers.METHODS We collected exhaled breath from histologically proven PDAC patients,radiological diagnosis IPMN,and healthy volunteers using the ReCIVA®device between 10/2021-11/2022.VOCs were identified by thermal desorption-gas chromatography/field-asymmetric ion mobility spectrometry and compared between groups.RESULTS A total of 156 participants(44%male,mean age 62.6±10.6)were enrolled(54 PDAC,42 IPMN,and 60 controls).Among the nine VOCs identified,two VOCs that showed differences between groups were dimethyl sulfide[0.73 vs 0.74 vs 0.94 arbitrary units(AU),respectively;P=0.008]and acetone dimers(3.95 vs 4.49 vs 5.19 AU,respectively;P<0.001).After adjusting for the imbalance parameters,PDAC showed higher dimethyl sulfide levels than the control and IPMN groups,with adjusted odds ratio(aOR)of 6.98(95%CI:1.15-42.17)and 4.56(1.03-20.20),respectively(P<0.05 both).Acetone dimer levels were also higher in PDAC compared to controls and IPMN(aOR:5.12(1.80-14.57)and aOR:3.35(1.47-7.63),respectively(P<0.05 both).Acetone dimer,but not dimethyl sulfide,performed better than CA19-9 in PDAC diagnosis(AUROC 0.910 vs 0.796).The AUROC of acetone dimer increased to 0.936 when combined with CA19-9,which was better than CA19-9 alone(P<0.05).CONCLUSION Dimethyl sulfide and acetone dimer are VOCs that potentially distinguish PDAC from IPMN and healthy participants.Additional prospective studies are required to validate these findings.

Static Stretching Combined with Conscious Slower Breathing May Increase Parasympathetic Activity and Reduce Stress in Adult Women

Background: Women are thought to be more susceptible to stress than men in a stressful society, and reducing stress is crucial for women to maintain their health. Static stretching (SST) is applied in various fields to not only increase muscle flexibility but also reduce stress. Additionally, conscious slower breathing (CSB) predominates parasympathetic activity, causing a relaxing effect. These results indicate that combining SST and CSB may be more useful in reducing stress. However, to the best of our knowledge, the effect of this combination remains unclear. Objective: This study aimed to elucidate the effects of the combination of SST and CSB on autonomic activity and stress in adult women. Methods: Eleven healthy Japanese adult female participants performed SST with nonconscious natural breathing for 20 min. The same participants performed SST in combination with CSB (2 s inspiratory and 4 s expiratory) for 20 min on another day. Salivary cortisol and chromogranin A levels were measured before and after stretching as stress markers of the hypothalamic-pituitary-adrenal axis and sympathetic nervous system. The coefficient of variation of the R-R interval (CVR-R) and high-frequency component (HF), which reflect parasympathetic nerve activity, and heart rate and low-frequency component (LF)/HF ratio, which reflect sympathetic nerve activity, were measured before, during, and after stretching. Results: SST decreased cortisol levels but with no significant changes in chromogranin A, heart rate, CVR-R, HF, or LF/HF ratio. The combination of SST and CSB increased CVR-R and HF levels in addition to decreasing cortisol levels but with no significant changes in chromogranin A, heart rate, or LF/HF levels. Conclusion: These results indicate that the combination of SST and CSB may increase parasympathetic activity and reduce stress. However, future randomized controlled trials with larger sample sizes should support this conclusion.

Analysis of the Effect of Psychological Nursing Combined with Breathing Exercises in Improving Lung Function in Patients with Pneumoconiosis

Objective: To analyze the effect of psychological nursing combined with breathing exercises on lung function of patients with pneumoconiosis, and to analyze the methods. A total of 64 cases of pneumoconiosis admitted from January 2020 to December 2022 were divided into the reference group and the experimental group by random numerical table. On the basis of symptomatic treatment, the control group was combined with conventional nursing measures and breathing exercises, while the experimental group was treated with psychological nursing on the basis of the control group, and the pulmonary function indexes and adverse mood of the two groups before and after nursing were compared. Results: There was no difference in SAS score, SDS score and pulmonary function indexes between the two groups before intervention (P > 0.05), and the SAS score in the experimental group was the SDS score was lower than that of the control group, and FEV1, FEV1% and FEV1/FVC were higher than those of the control group, and the P < 0.05 was lower.

The Importance of Breathing Training in Folk Dance Teaching

The importance of breathing training in dance teaching is reflected in the two aspects of enhancing the quality of dance movements and sublimating the connotation of dance movements.For example,high-quality breathing can help performers complete the dance movements and improve the coordination of the movements;at the same time,the unique body rhythm formed by breathing can strengthen the visual effect of the performance and convey its spirit and soul to the audience.This requires folk dance teachers to carry out relevant training and teaching activities based on the categories and skills of dance breathing,such as changing students’ideological cognition,developing periodic breathing training courses,providing personalized guidance to students,and allowing students to adjust their learning and practice methods in the evaluation.

Application of Deep Inspiration Breath Hold Technique in Radiotherapy After Breast- Conserving Surgery for Left Breast Cancer and Its Improvement on Cardiac Dose

Objective:To analyze the application of deep inspiration breath hold technique in radiotherapy after breast-conserving surgery for left breast cancer and the improvement of cardiac dose.Methods:A total of 45 patients with left breast cancer treated in our hospital after breast-conserving surgery were selected,and the selection time was set from January 2020 to August 2022.All patients received radiotherapy.The right breast,heart,and lung volumes,and dose parameters of the heart,lungs,right breast,and left anterior descending coronary artery were compared under free breathing(FB)and deep inspiration breath hold(DIBH)technical modes.Results:The heart volume of the DIBH group was smaller than that of the FB group,and the left and right lung volumes were significantly larger than those of the FB group.In the DIBH group,the heart dose parameters V5,proper lung dose parameters,and left anterior descending coronary artery dose parameters were found lower than that of the FB group,and the differences were statistically significant(P<0.05).Conclusion:Compared with FB,the DIBH technique can reduce the heart’s size and increase the lung volume when used for radiotherapy after breast-conserving surgery for left breast cancer.It also reduces the dose to the heart,right lung,and left anterior descending coronary artery,thus protecting the heart and lungs.

Ability of lactulose breath test results to accurately identify colorectal polyps through the measurement of small intestine bacterial overgrowth

BACKGROUND While colorectal polyps are not cancerous,some types of polyps,known as adenomas,can develop into colorectal cancer over time.Polyps can often be found and removed by colonoscopy;however,this is an invasive and expensive test.Thus,there is a need for new methods of screening patients at high risk of developing polyps.AIM To identify a potential association between colorectal polyps and small intestine bacteria overgrowth(SIBO)or other relevant factors in a patient cohort with lactulose breath test(LBT)results.METHODS A total of 382 patients who had received an LBT were classified into polyp and non-polyp groups that were confirmed by colonoscopy and pathology.SIBO was diagnosed by measuring LBTderived hydrogen(H)and methane(M)levels according to 2017 North American Consensus recommendations.Logistic regression was used to assess the ability of LBT to predict colorectal polyps.Intestinal barrier function damage(IBFD)was determined by blood assays.RESULTS H and M levels revealed that the prevalence of SIBO was significantly higher in the polyp group than in the non-polyp group(41%vs 23%,P<0.01;71%vs 59%,P<0.05,respectively).Within 90 min of lactulose ingestion,the peak H values in the adenomatous and inflammatory/hyperplastic polyp patients were significantly higher than those in the non-polyp group(P<0.01,and P=0.03,respectively).In 227 patients with SIBO defined by combining H and M values,the rate of IBFD determined by blood lipopolysaccharide levels was significantly higher among patients with polyps than those without(15%vs 5%,P<0.05).In regression analysis with age and gender adjustment,colorectal polyps were most accurately predicted with models using M peak values or combined H and M values limited by North American Consensus recommendations for SIBO.These models had a sensitivity of≥0.67,a specificity of≥0.64,and an accuracy of≥0.66.CONCLUSION The current study made key associations among colorectal polyps,SIBO,and IBFD and demonstrated that LBT has moderate potential as an alternative noninvasive screening tool for colorectal polyps.

Effects of ethanol and sex on propionate metabolism evaluated via a faster ^(13)C-propionate breath test in rats

BACKGROUND Alcoholism is regarded as a risk factor for vitamin B_(12)(VB_(12))deficiency.Because V B_(12) serves as a coenzyme of methylmalonyl-CoA mutase,a key enzyme in propionate metabolism,the ^(13)C-propionate breath test(PBT)has been studied as a non-invasive diagnostic modality for VB_(12) deficiency.However,the conventional PBT requires 2 h,which is inconvenient in clinical practice.We hypothesized that a faster PBT can be used to evaluate propionate metabolism and is more easily adaptable for clinical practice.AIM To evaluate a faster PBT for assessing the effects of long-term ethanol consumption on propionate metabolism in ethanol-fed rats(ERs).METHODS ERs were obtained by replacing standard drinking water(for control rats,CRs)with 16%ethanol solution in descendants of F344/DuCrj rats.Faster PBT was performed by administering ^(13)C-propionate aqueous solution to male and female ERs and CRs by inserting a metal tubule from the mouth to the stomach;exhaled gas was collected in a bag to measure its ^(13)CO_(2)/12CO_(2) isotope ratio via infrared isotope spectrometry.Serum VB_(12) and alanine transaminase(ALT)levels were measured via chemiluminescence immunoassay and the lactate dehydrogenaseultraviolet method,respectively.We evaluated statistical differences in mean body weight,change in ^(13)CO_(2)(Δ^(13)CO_(2)‰),peakΔ^(13)CO_(2)‰,and serum VB_(12) and ALT,between males and females and between ERs and CRs using the t-test and Mann-Whitney U test for normally and non-normally distributed variables,respectively.RESULTS Males weighed significantly more than females(P<0.001);CRs weighed significantly more than ERs(P<0.008).Δ^(13)CO_(2) reached a peak(C_(max))at 20 min and 30 min in females and males,respectively,decreasing after 20-30 min without rebound in all groups.Males had significantly higher C_(max) andΔ^(13)CO_(2) at 15-45 min than females(P<0.05;for all pairs).Propionate metabolism was enhanced in male ERs relative to male CRs,whereas metabolism did not differ markedly between ERs and CRs for females.Males had higher serum VB_(12) levels than females,without prominent differences between the ER and CR groups.Male CRs had notably higher ALT levels than male ERs.Thus,chronic ethanol consumption may trigger fatty acid production via intestinal bacteria and changes in gut microbiome composition.CONCLUSION Faster PBT shows that 16%ethanol consumption promotes propionate metabolism without inducing liver injury.This PBT may be used clinically to evaluate gut flora status.

Breath-by-breath measurement of exhaled ammonia by acetonemodifier positive photoionization ion mobility spectrometry via online dilution and purging sampling

Exhaled ammonia(NH_(3))is an essential noninvasive biomarker for disease diagnosis.In this study,an acetone-modifier positive photoionization ion mobility spectrometry(AM-PIMS)method was developed for accurate qualitative and quantitative analysis of exhaled NH_(3)with high selectivity and sensitivity.Acetone was introduced into the drift tube along with the drift gas as a modifier,and the characteristic NH_(3)product ion peak of(C_(3)H_(6)O)_(4)NH_(4)^(+)(K_(0)=1.45 cm^(2)/V·s)was obtained through the ion-molecule reaction with acetone reactant ions(C_(3)H_(6)O)_(2)H^(+)(K_(0)=1.87 cm^(2)/V·s),which significantly increased the peak-to-peak resolution and improved the accuracy of exhaled NH_(3)qualitative identification.Moreover,the interference of high humidity and the memory effect of NH_(3)molecules were significantly reduced via online dilution and purging sampling,thus realizing breath-by-breath measurement.As a result,a wide quantitative range of 5.87-140.92μmol/L with a response time of 40 ms was achieved,and the exhaled NH_(3)profile could be synchronized with the concentration curve of exhaled CO_(2).Finally,the analytical capacity of AM-PIMS was demonstrated by measuring the exhaled NH_(3)of healthy subjects,demonstrating its great potential for clinical disease diagnosis.

Conscious Slower Breathing Predominates Parasympathetic Activity and Provides a Relaxing Effect, in Healthy Japanese Adult Women

Background: The optimal breathing pattern (BP) to effectively regulate autonomic nervous activity is yet to be determined. Objective: We aimed to clarify the effects of four BPs (BP-1, BP-2, BP-3, and BP-4) on autonomic nervous activity and mood changes. Methods: Eleven healthy adult female volunteers performed each BP in a sitting position for 5 min in a resting state. The time required for one breathing for BP-1 (30 breaths/min), BP-2 (20 breaths/min), BP-3 (15 breaths/min), and BP-4 (10 breaths/min) were 2 s, 3 s, 4 s, and 6 s, respectively. The inspiratory/expiratory time of one breathing was 1 s/1 s, 1 s/2 s, 2 s/2 s, and 2 s/4 s. The high-frequency component (HF) and low-frequency component (LF)/HF ratio during and before (control) performing a BP were calculated from heart rate variability data recorded using the wearable biometric information tracer M-BIT. Three mood changes, which are, “pleasure—unpleasure”, “relaxation—tension”, and “sleepiness—arousal”, in the subjects were assessed using the visual analog scale (VAS) before and after performing a BP. Results: Slower breathing induced an increase in HF power and a reduction in LF/HF ratio, indicating increased parasympathetic activity and decreased sympathetic dominance. Furthermore, VAS revealed that slower breathing increased the tendency to feel “pleasure”, “relaxation”, and “sleepiness”. Conclusion: Our results suggest that slower breathing predominates parasympathetic activity in the autonomic nervous system, resulting in a relaxing effect. This result may help lay the foundation for deriving breathing methods that efficiently regulate an individual’s autonomic activity.

Recognition System for Diagnosing Pneumonia and Bronchitis Using Children’s Breathing Sounds Based on Transfer Learning

Respiratory infections in children increase the risk of fatal lung disease,making effective identification and analysis of breath sounds essential.However,most studies have focused on adults ignoring pediatric patients whose lungs are more vulnerable due to an imperfect immune system,and the scarcity of medical data has limited the development of deep learning methods toward reliability and high classification accuracy.In this work,we collected three types of breath sounds from children with normal(120 recordings),bronchitis(120 recordings),and pneumonia(120 recordings)at the posterior chest position using an off-the-shelf 3M electronic stethoscope.Three features were extracted from the wavelet denoised signal:spectrogram,mel-frequency cepstral coefficients(MFCCs),and Delta MFCCs.The recog-nition model is based on transfer learning techniques and combines fine-tuned MobileNetV2 and modified ResNet50 to classify breath sounds,along with software for displaying analysis results.Extensive experiments on a real dataset demonstrate the effectiveness and superior performance of the proposed model,with average accuracy,precision,recall,specificity and F1 scores of 97.96%,97.83%,97.89%,98.89%and 0.98,respectively,achieving superior performance with a small dataset.The proposed detection system,with a high-performance model and software,can help parents perform lung screening at home and also has the potential for a vast screening of children for lung disease.

The IOMT-Based Risk-Free Approach to Lung Disorders Detection from Exhaled Breath Examination

The lungs are the main fundamental part of the human respiratory system and are among the major organs of the human body.Lung disorders,including Coronavirus(Covid-19),are among the world’s deadliest and most life-threatening diseases.Early and social distance-based detection and treatment can save lives as well as protect the rest of humanity.Even though X-rays or Computed Tomography(CT)scans are the imaging techniques to analyze lung-related disorders,medical practitioners still find it challenging to analyze and identify lung cancer from scanned images.unless COVID-19 reaches the lungs,it is unable to be diagnosed.through these modalities.So,the Internet of Medical Things(IoMT)and machine learning-based computer-assisted approaches have been developed and applied to automate these diagnostic procedures.This study also aims at investigating an automated approach for the detection of COVID-19 and lung disorders other than COVID-19 infection in a non-invasive manner at their early stages through the analysis of human breath.Human breath contains several volatile organic compounds,i.e.,water vapor(5.0%–6.3%),nitrogen(79%),oxygen(13.6%–16.0%),carbon dioxide(4.0%–5.3%),argon(1%),hydro-gen(1 ppm)(parts per million),carbon monoxide(1%),proteins(1%),isoprene(1%),acetone(1%),and ammonia(1%).Beyond these limits,the presence of a certain volatile organic compound(VOC)may indicate a disease.The proposed research not only aims to increase the accuracy of lung disorder detection from breath analysis but also to deploy the model in a real-time environment as a home appliance.Different sensors detect VOC;microcontrollers and machine learning models have been used to detect these lung disorders.Overall,the suggested methodology is accurate,efficient,and non-invasive.The proposed method obtained an accuracy of 93.59%,a sensitivity of 89.59%,a specificity of 94.87%,and an AUC-Value of 0.96.

利用Breath Figure法制备具有Honeycomb结构的有机/无机复合膜

以聚苯乙烯和正硅酸乙酯的有机溶液为铸膜溶液,利用Breath Figure法制备了PS/SiO2 Honeycomb结构复合膜.采用SEM对复合膜进行了形貌分析,探讨了聚合物浓度、PS/TEOS配比、聚合物的结构、溶剂等对膜Honeycomb结构的影响.研究结果表明,聚合物浓度在20～50mg/mL,PS/TEOS质量比大于2∶1的条件下可以制备结构完整的多孔膜,且制备的Honeycomb结构在0.8cm2内无缺陷;采用双羧基封端的聚苯乙烯成膜效果好于单羧基封端的成膜效果;以氯仿和苯作为溶剂均可以制备完全Honeycomb结构的复合膜,但以苯为溶剂制备的多孔膜孔径较大.成膜中TEOS水解不完全,复合膜中混杂着未完全水解的TEOS以及SiO2.EDS面扫描分析表明,Si和O均匀地分散在复合膜中.

Breath Figure法制备聚碳酸酯(PC)蜂窝状多孔膜

以单组分聚碳酸酯(PC)为膜材质,在一定的湿度环境下,利用Breath Figure法在玻璃基板上成功制备了蜂窝状孔结构的聚碳酸酯多孔膜。研究了溶剂、溶液浓度和湿度对所成多孔膜结构和形貌的影响。实验结果表明,采用二氯甲烷为溶剂所制得的孔结构规整,排列均匀紧密,孔径大小为(3.30±0.19)μm,而以三氯甲烷为溶剂只能得到孔径大小不均且无紧密排列的孔。环境湿度从43%增加到91%,孔径大小由(2.28±0.63)μm增加到(9.07±1.42)μm,且湿度与孔大小基本上呈现一阶线性关系,通过理论推导得出直线斜率为0.15μm/%,即在此体系中湿度每增加1%,所形成的孔大小增加0.15μm。

Breathing Television:A Breathing Controlled Multimedia Player for Reducing Breathing Rate

We have designed a breathing paced television;a television that plays content in sync with users’ activity of exhaling through pursed lips, to achieve better motivation and compliance of such exercises. Described system has been tested with control group who have watched the same video. Breathing rate reduction was significantly higher in active group (54.48% ± 8.34%) than in control group (6.84% ± 17.21%), however, the proposed method of watching television is obviously not as trivial as watching television per se.

Comparisons of Image Quality and ADCs in Breath-Hold, Respiratory-Triggered and Free-Breathing DWI of Pancreas at 3-T

Objective: To compare image quality and apparent diffusion coefficients (ADC) of the normal pancreas parenchymas in breath-hold, respiratory-triggered and free-breathing diffusion weighted imaging (DWI) at 3.0-Tesla. Methods: DWI of the pancreas was performed at 3.0-Tesla in 21 healthy volunteers with breath-hold, respiratory-triggered and free-breathing using b-values of 0 and 500 s/mm2. For all three sequences, two readers assigned an image quality score to images at b0 and b500, and two independent readers measured ADCs for the head, body and tail of pancreas. Image quality scores and ADCs of pancreas in the three DWIs were compared. Results: For b0, image quality scores was not significantly different among the three sequences (p = 0.103). For b500, image quality score was significantly lower in free-breathing DWI than breath-hold or respiratory-triggered DWI (p = 0.000), and not significantly different between breath-hold and respiratory-triggered DWI (p = 0.212). Mean ADCs differed significantly among the anatomical regions with the lowest values measured in the pancreatic tail both at breath-hold and respiratory-triggered DWIs whereas no significant difference was found at free-breathing DWI. Conclusion: Breath-hold or respiratory-triggered technique provided DW images of pancreas with acceptable quality at 3.0-Tesla. Breath-hold is the preferred DWI technique for ADC measurements of pancreas.

Breath Figures法制备漆酚铜聚合物多孔膜

以漆酚铜聚合物(UCP)有机溶液为铸膜液,采用Breath Figures法制备漆酚铜聚合物多孔膜,探讨了溶剂、环境相对湿度和潮湿气体流速等因素对多孔膜形貌的影响,并使用红外光谱和扫描电镜等进行表征。结果表明,以二硫化碳为溶剂,在静态(潮湿气体流速为0mL/min,湿度为95%)或动态(潮湿气体流速为400mL/min,湿度为85%)时,均可制得孔分布均匀、孔型规整、优良耐热性和耐酸碱性的疏水性UCP多孔膜,其平均孔径分别为1.5和0.85μm。

Accuracy of urea breath test in Helicobacter pylori infection: Meta-analysis

AIM: To quantitatively summarize and appraise the available evidence of urea breath test(UBT) use to diagnose Helicobacter pylori(H. pylori) infection in patients with dyspepsia and provide pooled diagnostic accuracy measures.METHODS: We searched MEDLINE, EMBASE, Cochrane library and other databases for studies addressing the value of UBT in the diagnosis of H. pylori infection. We included cross-sectional studies that evaluated the diagnostic accuracy of UBT in adult patients with dyspeptic symptoms. Risk of bias was assessed using QUADAS(Quality Assessment of Diagnostic Accuracy Studies)-2 tool. Diagnostic accuracy measures were pooled using the random-effects model. Subgroup analysis was conducted by UBT type(13C vs 14C) and by measurement technique(Infrared spectrometry vs Isotope Ratio Mass Spectrometry).RESULTS: Out of 1380 studies identified, only 23 met the eligibility criteria. Fourteen studies(61%) evaluated 13 C UBT and 9 studies(39%) evaluated 14 C UBT. There was significant variation in the type of reference standard tests used across studies.Pooled sensitivity was 0.96(95%CI: 0.95-0.97) andpooled specificity was 0.93(95%CI: 0.91-0.94). Likelihood ratio for a positive test was 12 and for a negative test was 0.05 with an area under thecurve of 0.985. Meta-analyses were associated with a significant statistical heterogeneity that remained unexplained after subgroup analysis. The included studies had a moderate risk of bias.CONCLUSION: UBT has high diagnostic accuracy for detecting H. pylori infection in patients with dyspepsia. The reliability of diagnostic meta-analytic estimates however is limited by significant heterogeneity.