bluuebunny/crossref_metadata_2025 huggingface dataset:
Lacking Effects of Envelope Transcranial Alternating Current Stimulation Indicate the Need to Revise Envelope Transcranial Alternating Current Stimulation Methods
Authors: Erkens Jules , Schulte Michael , Vormann Matthias , Herrmann Christoph S
Published: July 2020

In recent years, several studies have reported beneficial effects of transcranial alternating current stimulation (tACS) in experiments regarding sound and speech perception. A new development in this field is envelope-tACS: The goal of this method is to improve cortical entrainment to the speech signal by stimulating with a waveform based on the speech envelope. One challenge of this stimulation method is timing; the electrical stimulation needs to be phase-aligned with the naturally occurring cortical entrainment to the auditory stimuli. Due to individual differences in anatomy and processing speed, the optimal time-lag between presentation of sound and applying envelope-tACS varies between participants. To better investigate the effects of envelope-tACS, we performed a speech comprehension task with a larger amount of time-lags than previous experiments, as well as an equal amount of sham conditions. No significant difference between optimal stimulation time-lag condition and best sham condition was found. Further investigation of the data revealed a significant difference between the positive and negative half-cycles of the stimulation conditions but not for sham. However, we also found a significant learning effect over the course of the experiment which was of comparable size to the effects of envelope-tACS found in previous auditory tACS studies. In this article, we discuss possible explanations for why our findings did not match up with those of previous studies and the issues that come with researching and developing envelope-tACS.
Tumor-associated myeloid cells provide critical support for T-ALL
Authors: Lyu Aram , Triplett Todd A. , Nam Seo Hee , Hu Zicheng , Arasappan Dhivya , Godfrey Wesley H. , Ames Rachel Y. , Sarang Adviti , Selden Hilary J. , Lee Chang-Han , Georgiou George , Horton Terzah M. , Ehrlich Lauren I. R.
Published: July 2020

Despite harboring mutations in oncogenes and tumor suppressors that promote cancer growth, T-cell acute lymphoblastic leukemia (T-ALL) cells require exogenous cells or signals to survive in culture. We previously reported that myeloid cells, particularly dendritic cells, from the thymic tumor microenvironment support the survival and proliferation of primary mouse T-ALL cells in vitro. Thus, we hypothesized that tumor-associated myeloid cells would support T-ALL in vivo. Consistent with this possibility, in vivo depletion of myeloid cells results in a significant reduction in leukemia burden in multiple organs in 2 distinct mouse models of T-ALL and prolongs survival. The impact of the myeloid compartment on T-ALL growth is not dependent on suppression of antitumor T-cell responses. Instead, myeloid cells provide signals that directly support T-ALL cells. Transcriptional profiling, functional assays, and acute in vivo myeloid-depletion experiments identify activation of IGF1R as a critical component of myeloid-mediated T-ALL growth and survival. We identify several myeloid subsets that have the capacity to directly support survival of T-ALL cells. Consistent with mouse models, myeloid cells derived from human peripheral blood monocytes activate IGF1R and directly support survival of primary patient T-ALL cells in vitro. Furthermore, enriched macrophage gene signatures in published clinical samples correlate with inferior outcomes for pediatric T-ALL patients. Collectively, these data reveal that tumor-associated myeloid cells provide signals critical for T-ALL growth in multiple organs in vivo and implicate tumor-associated myeloid cells and associated signals as potential therapeutic targets.
HIF-1 directly induces TET3 expression to enhance 5-hmC density and induce erythroid gene expression in hypoxia
Authors: Cao John Z. , Liu Hui , Wickrema Amittha , Godley Lucy A.
Published: July 2020

In mammalian cells, cytosines found within cytosine guanine dinucleotides can be methylated to 5-methylcytosine (5-mC) by DNA methyltransferases and further oxidized by the Ten-eleven translocation dioxygenase (TET) enzymes to 5-hydroxymethylcytosine (5-hmC). We have previously shown that hematopoietic stem and progenitor cells (HSPCs) with TET2 mutations have aberrant 5-hmC distribution and less erythroid differentiation potential. However, these experiments were performed under standard tissue culture conditions with 21% oxygen (O2), whereas HSPCs in human bone marrow reside in ∼1% O2. Therefore, to model human erythropoiesis more accurately, we compared 5-hmC distribution and gene expression in hypoxic vs normoxic conditions. Despite TET enzymes having limited O2 as a substrate in hypoxia, 5-hmC peaks were more numerous and pronounced than in normoxia. Among the TET genes, TET3 was upregulated specifically in hypoxia. We identified 2 HIF-1 binding sites in TET3 by chromatin immunoprecipitation of HIF-1α followed by sequencing, and TET3 upregulation was abrogated with deletion of both sites, indicating that TET3 is a direct HIF-1 target. Finally, we showed that loss of one or both of these HIF-1 binding sites in K562 cells disrupted erythroid differentiation in hypoxia and lowered cell viability. This work provides a molecular link between O2 availability, epigenetic modification of chromatin, and erythroid differentiation.
Stroke mimics in patients clinically diagnosed with stroke at a tertiary teaching hospital in Tanzania: a prospective cohort study
Authors: Matuja Sarah Shali , Khanbhai Khuzeima , Mahawish Karim M. , Munseri Patricia
Published: July 2020

Background

Stroke mimics account for up to one-third of acute stroke admissions and are a heterogeneous entity which pose diagnostic challenges. Diagnosing such patients is however crucial to avoid delays in treatment and potentially harmful medication prescription. We aimed at describing the magnitude, clinical characteristics and short-term outcomes of stroke mimics in patients clinically diagnosed with a stroke.

Methods

This prospective study enrolled patients admitted with a World Health Organization clinical criteria for stroke at a tertiary hospital in Tanzania. Baseline data was collected and the simplified version of the FABS scale was used to determine its usefulness in predicting stroke mimics. The National Institute of Health Stroke Scale and Modified Rankin Scale were used to assess for admission stroke severity and outcomes respectively.

Results

Among 363 patients with suspected stroke on admission, the final diagnosis was stroke mimics in 24 (6.6%) who had a mean age of 65.8 ± 15 years. Patients with stroke mimics were less likely to have cardiovascular risk factors for stroke including premorbid hypertension (7 (29.2%) vs 263 (77.6%), p < 0.001) and increased waist-hip ratio (9 (37.5%) vs 270 (79.6%) p < 0.001) for mimics and true strokes respectively. Clinical findings such as hypertension and the presence of cortical features in neurological examination occurred less in patients with stroke mimics. The simplified FABS score of ≥3 could identify patients with stroke mimics with a sensitivity and specificity of 38 and 80% respectively. The most common causes of mimics were brain tumors 6 (25%), meningoencephalitis 4 (16.7%) and epileptic seizures 3 (12.5%). The majority of patients with stroke mimics had severe disease on admission and the 30-day mortality in these patients was 54.5%.

Conclusions

In the present study, the proportion of stroke mimics among patients clinically diagnosed with stroke was 6.6% and brain tumors was a common etiology. Stroke mimics were less likely to have cardiovascular risk factors and cortical signs during evaluation. We recommend further studies that can help develop clinical scales used for predicting stroke mimics in an African population.
Early strategy of scepter XC balloon angioplasty and simultaneous Nimodipine infusion for vasospasm following ruptured aneurysm
Authors: Chen Chun-Ting , Chen Ching-Chang , Wang Alvin Yi-Chou , Wu Yi-Ming , Chin Shy-Chyi , Hsieh Po-Chuan , Yeap Mun-Chun , Hsu Shih-Yuan , Lin Ya-Jui
Published: July 2020

Background

Cerebral vasospasm still results in high morbidity and mortality rates in patients after aneurysmal subarachnoid hemorrhage (SAH). The aim of this study was to establish a protocol for the management of vasospasm and demonstrate our experience of angioplasty using the Scepter XC balloon catheter.

Methods

In this retrospective study, a computed tomography angiography and perfusion image was arranged if early symptoms occurred or on the 7th day following aneurysmal SAH. In patients with clear consciousness, balloon angioplasties were performed for symptomatic vasospasms, which were not improved within 6–12 h after maximal medical treatments. In unconscious patients, balloon angioplasties were performed for all patients with angiographic vasospasms.

Results

Fifty patients underwent Scepter XC balloon angioplasty among 396 consecutive patients who accepted endovascular or surgical treatments for ruptured aneurysms. All angioplasty procedures were successful without complications. 100% angiographic improvement and 94% clinical improvement were reached immediately after the angioplasties. A favorable functional outcome (modified Rankin Score of ≤2) could be achieved in 82% of patients. Even in patients with poor clinical grading (Hunt–Hess grade 4–5), a clinical improvement rate of 87.5% and favorable outcome rate was 70.8% could be achieved.

Conclusion

Balloon angioplasty with Scepter XC balloon catheter is safe and effective for post-SAH vasospasm. This device’s extra-compliant characteristics could considerably improve the quality of angioplasty procedures. For all patients, even those with poor neurological status, early treatment with combined protocol of nimodipine and angioplasty can have good clinical outcomes.
Males are more sensitive to reward and less sensitive to loss than females among people with internet gaming disorder: fMRI evidence from a card-guessing task
Authors: Zhang Jialin , Hu Yan , Wang Ziliang , Wang Min , Dong Guang-Heng
Published: July 2020

Background

Many studies have found an interesting issue in the Internet gaming disorder (IGD): males are always observed to be the majority. However, there are little research to exploring the differences in the neural mechanisms between males and females in decision-making process among people with IGD. Therefore, explore the reward/loss processing between different gender with IGD could help in understanding the underlying neural mechanism of IGD.

Methods

Data from functional magnetic resonance imaging (fMRI) were collected from 111 subjects (IGD: 29 males, 25 females; recreational internet game user (RGU): 36 males, 21 females) while they were performing a card-guessing task. We collected and compared their brain features when facing the win and loss conditions in different groups.

Results

For winning conditions, IGD group showed hypoactivity in the lingual gyrus than RGU group, male players showed hyperactivity in the left caudate nucleus, bilateral cingulate gyrus, right middle frontal gyrus (MFG), right precuneus and inferior parietal lobule relative to the females. And significant sex-by-group interactions results showed higher brain activities in the thalamus, parahippocampal gyrus and lower brain activities in Inferior frontal gyrus (IFG) were observed in males with IGD than females. For losing conditions, IGD group showed hypoactivity in the left lingual gyrus, parahippocampal gyrus and right anterior cingulate cortex (ACC) compared to the RGU group, male players showed hyperactive left caudate nucleus and hypoactive right middle occipital gyrus relative to females. And significant sex-by-group interactions results showed that compared to females with IGD, males with IGD showed decreased brain activities in the IFG and lingual gyrus.

Conclusions

First, there appeared to be no difference in reward processing between the IGD and RGU group, but IGD showed less sensitivity to loss. Secondly, male players showed more sensitivity to rewards and less sensitivity to losses. Last but not least, males and females showed opposite activation patterns in IGD degree and rewards/losses processing. And male IGD subjects are more sensitive to reward and less sensitive to loss than females, which might be the reason for the gender different rates on IGD.
Predicting developmental dysplasia of the hip in at-risk newborns
Authors: Roposch Andreas , Protopapa Evangelia , Malaga-Shaw Olivia , Gelfer Yael , Humphries Paul , Ridout Deborah , Wedge John H.
Published: July 2020

Background

The development of developmental dysplasia of the hip can be attributed to several risk factors and often in combination with each other. When predicting the likelihood of developing this condition, clinicians tend to over and underestimate its likelihood of occurring.

Therefore, the study aim is to determine among at-risk newborns how to best predict developmental dysplasia of the hip (DDH) within 8 weeks post-partum.

Methods

Prospective cohort study in secondary care. Patient population included newborns at-risk for DDH – we assessed 13,276 consecutive newborns for the presence of DDH risk factors. Only newborns with at least one of the predefined risk factors and those showing an abnormal examination of the hip were enrolled (n = 2191). For the development of a risk prediction model we considered 9 candidate predictors and other variables readily available at childbirth.

The main outcome measure was ultrasonography at a median age of 8 weeks using consensus diagnostic criteria; outcome assessors were blinded.

Results

The risk model includes four predictors: female sex (OR = 5.6; 95% CI: 2.9–10.9; P <  0.001); first degree family history of DDH (OR = 4.5; 95% CI: 2.3–9.0; P <  0.001), birthweight > 4000 g (OR = 1.6; 95% CI: 0.6–4.2; P = 0.34), and abnormal examination of hip (OR = 58.8; 95% CI: 31.9, 108.5; P <  0.001). This model demonstrated excellent discrimination (C statistic = 0.9) and calibration of observed and predicted risk (P = 0.35). A model without the variable ‘hip examination’ demonstrated similar performance.

Conclusion

The risk model quantifies absolute risk of DDH within 8 weeks postpartum in at-risk newborns. Based on clinical variables readily available at the point of childbirth, the model will enhance parental counselling and could serve as the basis for real time decisions prior to discharge from maternity wards.
Medical termination for pregnancy in early first trimester (≤ 63 days) using combination of mifepristone and misoprostol or misoprostol alone: a systematic review
Authors: Abubeker Ferid A. , Lavelanet Antonella , Rodriguez Maria I. , Kim Caron
Published: July 2020

Background

A wide range of drugs have been studied for first trimester medical abortion. Studies evaluating different regimens, including combination mifepristone and misoprostol and misoprostol alone regimens, show varying results related to safety, efficacy and other outcomes. Thus, the objectives of this systematic review were to compare the safety, effectiveness and acceptability of medical abortion and to compare medical with surgical methods of abortion ≤63 days of gestation.

Methods

Pubmed and EMBASE were systematically searched from database inception through January 2019 using a combination of MeSH, keywords and text words.

Randomized controlled trials on induced abortion at ≤63 days that compared different regimens of medical abortion using mifepristone and/or misoprostol and trials that compared medical with surgical methods of abortion were included.

We extracted data into a pre-designed form, calculated effect estimates, and performed meta-analyses where possible. The primary outcomes were ongoing pregnancy and successful abortion.

Results

Thirty-three studies composed of 22,275 participants were included in this review. Combined regimens using mifepristone and misoprostol had lower rates of ongoing pregnancy, higher rates of successful abortion and satisfaction compared to misoprostol only regimens. In combined regimens, misoprostol 800 μg was more effective than 400 μg. There was no significant difference in dosing intervals between mifepristone and misoprostol and routes of misoprostol administration in combination or misoprostol alone regimens. The rate of serious adverse events was generally low.

Conclusion

In this systematic review, we find that medical methods of abortion utilizing combination mifepristone and misoprostol or misoprostol alone are effective, safe and acceptable. More robust studies evaluating both the different combination and misoprostol alone regimens are needed to strengthen existing evidence as well as assess patient perspectives towards a particular regimen.
Ethnobotanical survey, anthelmintic effects and cytotoxicity of plants used for treatment of helminthiasis in the Central and Kara regions of Togo
Authors: Ataba Essoham , Katawa Gnatoulma , Ritter Manuel , Ameyapoh Adjoa Holali , Anani Kokou , Amessoudji Oukoe M. , Tchadié Pélagie Edlom , Tchacondo Tchadjabo , Batawila Komlan , Ameyapoh Yaovi , Hoerauf Achim , Layland Laura E. , Karou Simplice D.
Published: July 2020

Background

Traditional medicines are the main source of treatment of helminthiasis in endemic areas of Togo. The present study aimed to investigate the plants used by Traditional healers (THs) to treat helminth infections in endemic communities within the Central and Kara regions of Togo and to evaluate the anthelmintic activity of the three most cited plants.

Methods

An ethnobotanical survey was conducted from 19 to 24 June 2017 among traditional healers in the Central and Kara regions of Togo. The anthelmintic activity of the most cited plants namelyAframomum meleguetaK. Schum,Khaya senegalensisA. Juss andXylopia aethiopicaA. Rich, was evaluated using microfilariae (Mf) ofLitomosoides sigmodontis. The plants were evaluated for cytotoxicity according to the recommendation of NF EN ISO 10993-5 standard using the propidium iodide (PI) dye by flow cytometry on human peripheral blood mononuclear cells.

Results

A total of 197 THs were interviewed and 41 plant species were recorded. Leguminosae (14.6%) and Annonaceae (9.7%) families constitute the highest number of species cited for treatment of helminth infections.Afromomum meleguetawas the most cited by the THs for the treatment of onchocerciasis (UV = 0.036) whileX. aethiopicawas associated with the treatment of schistosomiasis (UV = 0.061) and lymphatic filariasis (UV = 0.061). There was a great agreement among the THs regarding ethnomedicinal uses of plants to treat helminthiasis with ICF values ranging from 0.57 to 0.67. The anthelmintic assay yielded lethal doses values of 233 μg/mL, 265 μg/mL and 550 μg/mL, respectively forX. aethiopica,A. meleguetaandK. senegalensis.Afromomum meleguetaandX. aethiopicapresented no cytotoxicity, less than 20% death, whereasK. senegalensisinduced moderate toxicity, 24 ± 8% death.

Conclusion

This study demonstrated the scientific rationale for the use of plants to treat helminthiasis in the Togolese traditional medicine. However, the use ofK. senegalensisrequires more caution since the plant is fairly toxic.

Trial Registration

NA
Making researchers responsible: attributions of responsibility and ambiguous notions of culture in research codes of conduct
Authors: Valkenburg Govert , Dix Guus , Tijdink Joeri , de Rijcke Sarah
Published: July 2020

Background

Research codes of conduct offer guidance to researchers with respect to which values should be realized in research practices, how these values are to be realized, and what the respective responsibilities of the individual and the institution are in this. However, the question ofhowthe responsibilities are to be divided between the individual and the institution has hitherto received little attention. We therefore performed an analysis of research codes of conduct to investigate how responsibilities are positioned as individual or institutional, and how the boundary between the two is drawn.

Method

We selected 12 institutional, national and international codes of conduct that apply to medical research in the Netherlands and subjected them to a close-reading content analysis. We first identified the dominant themes and then investigated how responsibility is attributed to individuals and institutions.

Results

We observed that the attribution of responsibility to either the individual or the institution is often not entirely clear, and that the notion ofcultureemerges as a residual category for such attributions. We see this notion of responsible research cultures as important; it is something that mediates between the individual level and the institutional level. However, at the same time it largely lacks substantiation.

Conclusions

While many attributions of individual and institutional responsibility are clear, the exact boundary between the two is often problematic. We suggest two possible avenues for improving codes of conduct: either to clearly attribute responsibilities to individuals or institutions and depend less on the notion of culture, or to make culture a more explicit concern and articulate what it is and how a good culture might be fostered.
Application of standardised effect sizes to hospital discharge outcomes for people with diabetes
Authors: Robbins Tim , Lim Choi Keung Sarah N. , Sankar Sailesh , Randeva Harpal , Arvanitis Theodoros N.
Published: July 2020

Background

Patients with diabetes are at an increased risk of readmission and mortality when discharged from hospital. Existing research identifies statistically significant risk factors that are thought to underpin these outcomes. Increasingly, these risk factors are being used to create risk prediction models, and target risk modifying interventions. These risk factors are typically reported in the literature accompanied by unstandardized effect sizes, which makes comparisons difficult. We demonstrate an assessment of variation between standardised effect sizes for such risk factors across care outcomes and patient cohorts. Such an approach will support development of more rigorous risk stratification tools and better targeting of intervention measures.

Methods

Data was extracted from the electronic health record of a major tertiary referral centre, over a 3-year period, for all patients discharged from hospital with a concurrent diagnosis of diabetes mellitus. Risk factors selected for extraction were pre-specified according to a systematic review of the research literature. Standardised effect sizes were calculated for all statistically significant risk factors, and compared across patient cohorts and both readmission & mortality outcome measures.

Results

Data was extracted for 46,357 distinct admissions patients, creating a large dataset of approximately 10,281,400 data points. The calculation of standardized effect size measures allowed direct comparison. Effect sizes were noted to be larger for mortality compared to readmission, as well as for being larger for surgical and type 1 diabetes cohorts of patients.

Conclusions

The calculation of standardised effect sizes is an important step in evaluating risk factors for healthcare events. This will improve our understanding of risk and support the development of more effective risk stratification tools to support patients to make better informed decisions at discharge from hospital.
The feasibility and safety of complete laparoscopic extended right hemicolectomy with preservation of the ileocecal junction in right-transverse colon cancer
Authors: Su Hao , Wu Hongliang , Mu Bing , Bao Mandula , Luo Shou , Zhao Chuanduo , Liu Qian , Wang Xishan , Zhou Zhixiang , Zhou Haitao
Published: July 2020

Background

To evaluate the feasibility and safety of a new surgical method, complete laparoscopic extended right hemicolectomy with preservation of the ileocecal junction in right-transverse colon cancer.

Methods

We retrospectively analyzed and compared the data of consecutive patients with right-transverse colon cancer who underwent complete laparoscopic extended right hemicolectomy with preservation of the ileocecal junction (n = 23) and conventional complete laparoscopic extended right hemicolectomy (n = 34) in our hospital between October 2017 to May 2019, respectively.

Results

The overall operation time of the ileocecal junction-preserved group was significantly shorter than that of the control group (p = 0.048). There was no difference in the number of harvested lymph nodes, metastatic lymph nodes, and rate of metastatic lymph nodes (p > 0.05). The ileocecal junction-preserved group showed shorter time of first flatus, lower frequency of postoperative diarrhea, and shorter duration of postoperative hospitalization. Furthermore, it also showed that the defecation frequency was lower in the ileocecal junction-preserved group than the control group on the 1st, 3rd, and 6th month (p < 0.05), and the number of patients who defecated at night or defecated four times or more a day was less in the ileocecal junction-preserved group than control group on the 1st month (p < 0.05).

Conclusion

The complete laparoscopic extended right hemicolectomy with preservation of the ileocecal junction promises as a safe and feasible surgical procedure for right-transverse colon cancer, associated with earlier recovery of bowel function, shorter operation time, and similar pathological outcomes when compared to the conventional laparoscopic procedure.
Hypoxia, metabolism, and the circadian clock: new links to overcome radiation resistance in high-grade gliomas
Authors: Shen Han , Cook Kristina , Gee Harriet E. , Hau Eric
Published: July 2020

Radiotherapy is the cornerstone of treatment of high-grade gliomas (HGGs). It eradicates tumor cells by inducing oxidative stress and subsequent DNA damage. Unfortunately, almost all HGGs recur locally within several months secondary to radioresistance with intricate molecular mechanisms. Therefore, unravelling specific underlying mechanisms of radioresistance is critical to elucidating novel strategies to improve the radiosensitivity of tumor cells, and enhance the efficacy of radiotherapy. This review addresses our current understanding of how hypoxia and the hypoxia-inducible factor 1 (HIF-1) signaling pathway have a profound impact on the response of HGGs to radiotherapy. In addition, intriguing links between hypoxic signaling, circadian rhythms and cell metabolism have been recently discovered, which may provide insights into our fundamental understanding of radioresistance. Cellular pathways involved in the hypoxic response, DNA repair and metabolism can fluctuate over 24-h periods due to circadian regulation. These oscillatory patterns may have consequences for tumor radioresistance. Timing radiotherapy for specific times of the day (chronoradiotherapy) could be beneficial in patients with HGGs and will be discussed.
Prevalence of hepatitis C in the adult population of Bulgaria: a pilot study
Authors: Sperle Ida , Nielsen Stine , Gassowski Martyna , Naneva Zlatina , Perchemlieva Tanya , Amato-Gauci Andrew , an der Heiden Matthias , Bremer Viviane , Golkocheva-Markova Elitsa , Hristov Kristiyan , Kaneva Elena , Simeonova Yanita , Tenev Tencho , Varleva Tonka , Duffell Erika , Zimmermann Ruth
Published: July 2020

Objective

This study piloted a European technical protocol for conducting chronic hepatitis C prevalence surveys in the general population. The pilot study took place in the Bulgarian city of Stara Zagora in 2018, and results of setting up, conducting and evaluating the survey are presented.

Results

A probability-based sample of the general adult population was drawn from the local population registry, stratified by age and sex. A sample size of 999 was calculated, and accounting for 50% non-response, 1998 registered invitation letters were sent. Venous blood samples and questionnaire data were collected by the Regional Health Inspectorate in Stara Zagora. Blood samples were tested for anti-HCV, and if reactive for RNA. 252 (21.6%) of the participants were included in the study. Mean age and sex distribution differed between the participants (55.9 years, 60.3% females) and the total sample (48.9 years, 53.4%). The weighted chronic HCV prevalence among participants was 0.9% [95% CI 0.2–4.2%]. The approach of only sending registered letters contributed to a low response rate, and more efforts are needed to reduce non-response, especially among men and younger age groups. Results of the evaluation were integrated in the final technical protocol.
Copper alloy production in the Warring States period (475-221 BCE) of the Shu state: a metallurgical study on copper alloy objects of the Baishoulu cemetery in Chengdu, China
Authors: Li Haichao , Zuo Zhiqiang , Cui Jianfeng , Tian Jianbo , Yang Yingdong , Yi Li , Zhou Zhiqing , Fan Jianan
Published: July 2020

Many bronze objects were unearthed in the capital of the Shu state in present-day Chengdu. However, only a few metallurgical studies have been carried out on those objects. This research attempts to study the alloy techniques and possible ore sources of 28 bronze objects recently excavated from the Baishoulu cemetery in Chengdu. Elemental composition and lead isotope ratios were measured, and metallographic observations were conducted. The results indicate that most objects were copper–tin–lead alloys with variable tin and lead content. The samples showed evidence of casting, as well as cold working and annealing techniques. The lead isotope data indicate that multiple lead sources were used in Baishoulu; however, the exact number is not yet known. Most of the lead sources in Baishoulu are the same as those in Zeng state bronze and Chu state bronze. In addition, some of the bronzes came from sources that were widely used in the Central Plains and surrounding regions. This new information aids in understanding the cultural interactions between Shu and other states. Moreover, some bronzes might have used local lead sources. Copper and tin sources were difficult to determine; however, the different trace elemental patterns between Baishoulu and Bayilu bronzes indicate different copper and tin sources might be used. Additionally, copper and lead may originate from different sources in the Shu state. Systematic data are necessary to disclose a possible metal source exchange network involving the Shu state in the Warring States period.
Accuracy of intraocular lens power calculation formulae after laser refractive surgery in myopic eyes: a meta-analysis
Authors: Li Hongyu , Nan Li , Li Jun , Song Hui
Published: July 2020

Background

To compare the accuracy of intraocular lens power calculation formulae after laser refractive surgery in myopic eyes.

Methods

We searched the databases on PubMed, EMBASE, Web of Science and the Cochrane library to select relevant studies published between Jan 1st, 2009 and Aug 11th, 2019. Primary outcomes were the percentages of refractive prediction error within ±0.5 D and ±1.0 D.

Results

The final meta-analysis included 16 studies using seven common methods (ASCRS average, Barrett True-K no history, Double-K SRK/T, Haigis-L, OCT formula, Shammas-PL, and Wang-Koch-Maloney). ASCRS average yielded significantly higher percentage of refractive prediction error within ±0.5 D than Haigis-L, Shammas-PL and Wang-Koch-Maloney (P = 0.009, 0.01, 0.008, respectively). Barrett True-K no history also yielded significantly higher percentage of refractive prediction error within ±0.5 D than Shammas-PL and Wang-Koch-Maloney (P = 0.01, P < 0.0001, respectively), and a similar result was found when comparing OCT formula with Haigis-L and Shammas-PL (P = 0.03, P = 0.01, respectively).

Conclusion

The ASCRS average or Barrett True-K no history should be used to calculate the intraocular lens power in eyes after myopic laser refractive surgery. The OCT formula if available, can also be a good alternative choice.
Mutual comparative analysis: a new topography-guided custom ablation protocol referencing subjective refraction to modify corneal topographic data
Authors: Cao Kaiwei , Liu Lina , Zhang Tao , Liu Ting , Bai Ji
Published: July 2020

Background

Several planning algorithms have been developed for topography-guided custom ablation treatment (T-CAT), but each has its own deficiencies. The purpose of this study is to demonstrate the potential of a novel mutual comparative analysis (MCA) informed by manifest refraction and corneal topographic data and the patient’s subjective perception in correcting ametropia.

Methods

This retrospective review included patients with significant preoperative differences in the power or axis of astigmatism according to the manifest refraction and corneal topographic data (power > 0.75 D and/or axis > 10°). T-CAT planning was designed using MCA. Follow-ups were conducted for at least 6 months.

Results

Seventy-nine patients (121 eyes) were included. The mean preoperative deviation in the astigmatic power and axis were 0.72 ± 0.43 D and 20.18 ± 23.68°, respectively. The average oculus residual astigmatism (ORA) was 0.81 ± 0.32 D (range: 0.08–1.66 D). Six months postoperatively, the mean spherical equivalent refraction was 0.04 ± 0.42 D, and the mean cylinder was − 0.27 ± 0.24 D. The mean efficacy and safety indices were 1.10 and 1.15, respectively. The uncorrected distance visual acuity in 92% of the eyes was the same or better than the corrected distance visual acuity. The angle of error was ±5° in 61% of eyes and ± 15° in 84% of eyes. Residual astigmatism was ≤0.5 D in 91% of eyes. Optical quality and photopic contrast sensitivity did not change significantly (p > 0.05), and the scotopic contrast sensitivity decreased at 3, 6, and 12 cpd (p < 0.05). The vertical coma and horizontal coma of the anterior corneal surface significantly decreased postoperatively but increased during follow-up.

Conclusions

The MCA demonstrated safety, efficacy, accuracy, predictability, and stability and can be used as a complementary and feasible method for T-CAT.
Average absorbed breast dose (2ABD): an easy radiation dose index for digital breast tomosynthesis
Authors: Traino Antonio C. , Barca Patrizio , Lamastra Rocco , Tucciariello Raffaele M. , Sottocornola Chiara , Marini Carolina , Aringhieri Giacomo , Caramella Davide , Fantacci Maria E.
Published: July 2020

Background

To propose a practical and simple method to individually evaluate the average absorbed dose for digital breast tomosynthesis.

Methods

The method is based on the estimate of incident air kerma (ka,i) on the breast surface. An analytical model was developed to calculate the ka,i from the tube voltage, tube load, breast thickness, x-ray tube yield, and anode-filter combination. A homogeneous phantom was employed to simulate the breast in experimental measurements and to assess the dose-depth relationship. The ka,i values were employed to calculate the “average absorbed breast dose” (2ABD) index. Four mammographic units were used to develop and test our method under many conditions close to clinical settings. The average glandular dose (AGD) calculated following the method described by Dance et al., and the 2ABD computed through our method (i.e., from the exposure parameters) were compared in a number of conditions.

Results

A good agreement was obtained between the ka,i computed through our model and that measured under different clinical conditions: discrepancies < 6% were found in all conditions. 2ABD matches with a good accuracy the AGD for a 100% glandular-breast: the minimum, maximum, and mean differences were < 0.1%, 7%, and 2.4%, respectively; the discrepancies increase with decreasing breast glandularity.

Conclusions

The proposed model, based on only few exposure parameters, represents a simple way to individually calculate an index, 2ABD, which can be interpreted as the average absorbed dose in a homogeneous phantom, approximating a 100% glandular breast. The method could be easily implemented in any mammographic device performing DBT.
High-resolution CT features of COVID-19 pneumonia in confirmed cases
Authors: Omar Suzan , Motawea Abdelghany Mohammed , Yasin Rabab
Published: July 2020

Background

Coronavirus (COVID-19) pneumonia emerged in Wuhan, China, in December 2019. It was highly contagious spreading all over the world, with a rapid increase in the number of deaths. COVID-19 is characterized by fever, fatigue, dry cough, and dyspnea with variable chest imaging features which have been detected.

In our study, we shared our experience of CT findings in proven cases of COVID-19 to recognize the different CT patterns to help in proper and accurate diagnosis.

Results

The most common CT features detected in COVID-19 cases were ground glass patches (93.3%) followed by subpleural linear abnormality (53.3%), air bronchogram (23.3%), and consolidation patches (23.3%), as well as bronchial wall thickening (16.7%), crazy paving pattern (13.3%), and discrete nodules surrounded by ground glass appearance (10%). Only one case had pleural effusion (3.3%). No cavitary lesions or specific lymph nodes were detected in any of the examined patients. The lung lesions showed typical diffuse, basal, and subpleural involvement with less affection of the upper lobes.

Conclusion

CT imaging findings of COVID-19 can help in early and accurate diagnosis of COVID-19 and proper assessment of the severity of the disease.
CT chest of COVID-19 patients: what should a radiologist know?
Authors: Ali Tamer F. , Tawab Mohamed A. , ElHariri Mona A
Published: July 2020

Background

The aim of current work is to review the CT findings of COVID-19 in a pictorial study to help the radiologists to be familiar to imaging findings of COVID-19.

Main body

Coronavirus disease 2019 (COVID-19) is a pandemic highly infectious disease which is first reported in December 2019 in Wuhan, China, and then had its outbreak leads to a global public health emergency. Real-time reverse transcription polymerase chain reaction (RT-PCR) of viral nucleic acid is considered as the reference standard for COVID-19 diagnosis; however, recent studies showed the importance of CT chest in the diagnosis of COVID-19 with high sensitivity.

The CT hallmarks of COVID-19 were bilateral peripheral ground-glass opacities, consolidation with the advance of the disease more consolidation is there with linear opacities and crazy-paving pattern as well as halo and reverse halo sign.

Conclusion

Early identification of COVID-19 cases is vital. The radiologist should be familiar with the possible findings. Further future studies with pathological correlation will help for more understanding of the imaging findings and its value in assessing of prognosis.
Experimental tests and numerical simulations of circular reinforced concrete piers under ship impact
Authors: Chen Zhiyue , Fang Hai , Zhu Lu , Mao Yifeng , Liu Weiqing
Published: July 2020

A growing number of bridge structures spanning over waterways are most susceptible to ship-pier collisions that may result in serious consequences such as ship sinking, failure and collapse of the bridge, even personal casualty, etc. To quantify the impact force and load, ship-pier impact tests and reliable numerical predictions should be carried out. This paper shows experimental tests and numerical simulation results of ship impact on bridge piers. To assess the performance of circular reinforced concrete piers against ship collisions and guide the design of bridge piers against impact, reduced-scale circular reinforced concrete (RC) piers were built and tested, and finite element (FE) simulations based on edge pier of junction pier of Wu-Song River Bridge were also conducted. To evaluate the reasonability of the damage process and failure mode of the pier due to ship impact more accurately, the bridge piers are modeled with nonlinear materials to simulate the bridge pier characteristics instead of rigid and elastic materials. Based on numerical results, the design impact loads prescribed by code current specifications such as Eurocode and AASHTO Bridge Design Specifications were evaluated and compared. To predict impact force, the fiber section model was employed to attain ultimate bearing capacity of the pier.
Performance of suspension bridge hangers exposed to hazardous material fires considering wind effects
Authors: Zou Qiling , Pool Kavi , Chen Suren
Published: July 2020

Traffic accidents involving vehicles transporting hazardous materials (HazMat) can cause serious fire hazards, threatening the safety of bridge infrastructure as well as nearby traffic. For critical bridges such as long-span cable-stayed and suspension bridges, fire hazards can not only cause severe structural damage, but also serious traffic disruption, congestion, and accidents. Unlike short-span bridges, long-span cable-supported bridges often experience considerable wind effects at the height of the bridge deck which can significantly influence fire hazards. As the critical components of cable-supported bridges, the failure of cables or hangers due to fire may trigger progressive failure of the bridge structure. Existing studies on fire simulation of long-span bridges, however, are very limited. Typical fire hazard scenarios from vehicles transporting hazardous material (HazMat) are simulated with fire dynamics simulation (FDS) software on a suspension bridge with a focus on the threats to hangers. To more realistically consider the potential fire hazards to bridge hangers of long-span bridges, appropriate fuel size, transverse offset distance, and wind effects are considered. The study of a baseline scenario is carried out first and followed by parametric studies to investigate the effects of wind speeds, longitudinal offsets, hazardous material types and spill sizes on the fire simulation results.
Petrophysical properties difference of organic-rich and organic-poor shale reservoir using low-field nuclear magnetic resonance experiment in the Sangzhi block, South China
Authors: Zhao Gang , Ding Wenlong , Sun Yaxiong , Shi Siyu , Jiao Baocheng , Tian Li , Chen Peng , Zhao Zhan , Sun Ning
Published: July 2020

The petrophysical properties of rocks have an important influence on shale quality. To characterize the difference of petrophysical properties between organic-rich and organic-poor shale reservoirs, we used the low-field nuclear magnetic resonance (NMR) technique and field emission scanning electron microscopy analysis after argon-ion polishing or natural section to measure porosity and permeability from six core samples from well SY6 in the Sangzhi block, Northwest Hunan province. Some information about pore types, pore structure, residual porosity, movable porosity, and permeability based on the T2 spectrums’ difference of organic-rich and organic-poor shale samples were discussed. The shale sample test results show that the main pores size is mesopore, which provide most of shale gas reservoir space. The continuous peaks demonstrated the pores’ connectivity better than the isolated peaks, and shale gas can migrate freely between these connected pores and fractures. The permeability of all samples calculated by the classic Coates model is extremely low, which is not conducive to the migration of shale gas. We evaluated the dominating factors of NMR porosity and permeability and found that the relationships between NMR porosity and permeability and total organic carbon content, quartz minerals, and clay minerals are not clear, which may be a comprehensive influence. The research results have important guiding significance for shale reservoir quality evaluation in this area.
Neuromuscular disease modeling on a chip
Authors: Santoso Jeffrey W. , McCain Megan L.
Published: July 2020

Organs-on-chips are broadly defined as microfabricated surfaces or devices designed to engineer cells into microscale tissues with native-like features and then extract physiologically relevant readouts at scale. Because they are generally compatible with patient-derived cells, these technologies can address many of the human relevance limitations of animal models. As a result, organs-on-chips have emerged as a promising new paradigm for patient-specific disease modeling and drug development. Because neuromuscular diseases span a broad range of rare conditions with diverse etiology and complex pathophysiology, they have been especially challenging to model in animals and thus are well suited for organ-on-chip approaches. In this Review, we first briefly summarize the challenges in neuromuscular disease modeling with animal models. Next, we describe a variety of existing organ-on-chip approaches for neuromuscular tissues, including a survey of cell sources for both muscle and nerve, and two- and three-dimensional neuromuscular tissue-engineering techniques. Although researchers have made tremendous advances in modeling neuromuscular diseases on a chip, the remaining challenges in cell sourcing, cell maturity, tissue assembly and readout capabilities limit their integration into the drug development pipeline today. However, as the field advances, models of healthy and diseased neuromuscular tissues on a chip, coupled with animal models, have vast potential as complementary tools for modeling multiple aspects of neuromuscular diseases and identifying new therapeutic strategies.
A Theoretical Study on a Novel Cartesian Product Operator Formalism Applicable to Strongly-Coupled Two-Spin 1/2 Systems in Solution-State and Solid-State MAS NMR Spectroscopy
Authors: Nakai Toshihito
Published: July 2020

In solution-state and solid-state MAS (Magic Angle Spinning) NMR (Nuclear Magnetic Resonance) spectroscopy, a comprehensive product operator formalism applicable to general two-spin 1/2 systems, including strongly-coupled systems, is proposed. The formalism employs standard product operators, based on the orthogonal coordinate system, easily evaluating the effects of RF (Radio Frequency) pulse sequences. Solid-state anisotropic interactions modulated by MAS are treated in the perturbation theory, yielding striking solid-state effects, whereas the absence of those interactions leads to solution-state cases with strong couplings. Solid-state MAS INADEQUATE spectra are found to give rise to auto-correlation signals even for the spin pairs possessing an identical isotropic chemical shift.
Sports Medicine Fellowship Training Improves Sport-related Concussion Evaluation
Authors: Northam Weston T. , Cools Michael J. , Chandran Avinash , Alexander Andrew , Mihalik Jason P. , Guskiewicz Kevin M. , Carneiro Kevin A.
Published: July 2020

Evaluating acute sport-related concussion (SRC) differs among providers, who apply international consensus and national guidelines variably. Retrospective medical record review was completed for 889 outpatients aged 7 to 18 years, diagnosed with SRC from 2014 to 2017. Associations between board-certified sports medicine fellowship (SMF) training status and assessment of concussion-specific history and physical examination items were tested using nonparametric χ2tests. Differential odds (by fellowship training status) of using history and physical examination items were assessed using multivariable logistic regression modeling. Each SRC history and physical examination items were assessed in higher proportions by SMFs, as compared with non-SMFs, statistically significant for all tested items with the exception of headache history. SMFs demonstrated higher odds of detailed neurologic examinations and clinical cognitive testing compared with non-SMFs, after adjusting for patient and physician characteristics. Physicians caring for concussed patients should seek continuing education opportunities aligning them with training provided to sports medicine fellows.