Quantitative analysis of noninvasive deep temporal interference stimulation: A simulation and experimental study

Background

Deep brain stimulation (DBS) is a method for stimulating deep regions of the brain for the treatment of various neurological and psychiatric disorders such as depression, obsessive-compulsive disorder, addiction, and Parkinson's disease. Generally, DBS can be performed using both invasive and non-invasive approaches. Invasive DBS is associated with several problems, including intracranial bleeding, infection, and changes in the position of the electrode tip. Temporal interference (TI) stimulation is a non-invasive technique used to stimulate deep regions of the brain by applying two high-frequency sinusoidal currents with slightly different frequencies.

New method

This paper presents insights into the response of the spiking in the Hodgkin-Huxley (HH) neuron model of the rat somatosensory cortex by changing the parameters carrier frequency, current ratio, and difference frequency of TI stimulation. Furthermore, in order to experimentally evaluate the effect of TI stimulation on the activation of the left motor cortex, an experiment was conducted to measure the motion induced by the balanced and unbalanced TI stimulation. In the experiment, a three-axis accelerometer was attached to the right hand of the animal to determine the position of the hand.

Results

Simulation results of the HH model showed that the frequency of the envelope of the TI stimulation is identical to the fundamental frequency of the neuron spikes. This result was obtained for difference frequencies of 6 Hz and 9 Hz in balanced and unbalanced TI stimulations. Moreover specifically, when the difference frequency is set to zero, the carrier frequency is within the range of 1300-1400 Hz, and the current range is between 140 and 250 μA/cm2, the firing rate reached to its highest value. In the experimental result, the maximum range of movement at a difference frequency of Δf = 6 Hz was approximately 1.6 mm and 5.3 mm in the z and y directions respectively.

Comparison with existing method

The results of the spatial spectrum of the rat hand movement were consistent with the spectrum information of the simulation results. Additionally, steering the interfering region to the left motor cortex leads to noticeable contralateral movement of the right hand while no movement was observed in the right hand during the stimulation of the right motor cortex.

Conclusion

This technique of stimulation for the deep regions of the brain is a promising tool to noninvasively treat various neurological and psychiatric disorders such as morphine dependence in addicted rats.

Osteonecrosis in Gaucher disease in the era of multiple therapies: Biomarker set for risk stratification from a tertiary referral center

Background

A salutary effect of treatments for Gaucher disease (GD) has been a reduction in the incidence of avascular osteonecrosis (AVN). However, there are reports of AVN in patients receiving enzyme replacement therapy (ERT) , and it is not known whether it is related to individual treatments, GBA genotypes, phenotypes, biomarkers of residual disease activity, or anti-drug antibodies. Prompted by development of AVN in several patients receiving ERT, we aimed to delineate the determinants of AVN in patients receiving ERT or eliglustat substrate reduction therapy (SRT) during 20 years in a tertiary referral center.

Methods

Longitudinal follow-ups of 155 GD patients between 2001 and 2021 were analyzed for episodes of AVN on therapy, type of therapy, GBA1 genotype, spleen status, biomarkers, and other disease indicators. We applied mixed-effects logistic model to delineate the independent correlates of AVN while receiving treatment.

Results

The patients received cumulative 1382 years of treatment. There were 16 episodes of AVN in 14 patients, with two episodes, each occurring in two patients. Heteroallelic p.Asn409Ser GD1 patients were 10 times (95% CI, 1.5-67.2) more likely than p.Asn409Ser homozygous patients to develop osteonecrosis during treatment. History of AVN prior to treatment initiation was associated with 4.8-fold increased risk of AVN on treatment (95% CI, 1.5-15.2). The risk of AVN among patients receiving velaglucerase ERT was 4.68 times higher compared to patients receiving imiglucerase ERT (95% CI, 1.67-13). No patient receiving eliglustat SRT suffered AVN. There was a significant correlation between GlcSph levels and AVN. Together, these biomarkers reliably predicted risk of AVN during therapy (ROC AUC 0.894, p<0.001).

Conclusions

There is a low, but significant risk of AVN in GD in the era of ERT/SRT. We found that increased risk of AVN was related to GBA genotype, history of AVN prior to treatment initiation, residual serum GlcSph level, and the type of ERT. No patient receiving SRT developed AVN. These findings exemplify a new approach to biomarker applications in a rare inborn error of metabolism to evaluate clinical outcomes in comprehensively followed patients and will aid identification of GD patients at higher risk of AVN who will benefit from closer monitoring and treatment optimization.

Funding

LSD Training Fellowship from Sanofi to MB.

Analysis of Fractures and Disability Defects Accidents in Lian Oil Company by Tripod Beta Technique

Introduction: Undoubtedly, the first step in controlling accidents is to analyze them to identify the root causes. In this study, the root causes of accidents leading to severe consequences have been analyzed using the beta tripod technique in Lian Oil Company. Materials and Methods: The research method is descriptive-analytical. In this research, the events of 2020 in two barrel-making and barrel filling units of Lian Oil Refining and Trade Company have been investigated. The tripod-beta method is one of the methods of tracing the roots of accidents, which is widely used in the oil industry because of its special attitude towards the element of human error. Using investigator software, a tripod beta diagram related to three fracture and disability accidents was drawn and after recording and identifying the relevant causes and obstacles, corrective measures were taken to prevent similar accidents. The basis of accident control is the creation of appropriate control and defense systems in such a way as to prevent the interconnection and interaction of the risk factor and the target factor. Results: The results of this study show that non-compliance with safety principles due to reduced staff awareness and lack of long-term and short-term training are the root causes of accidents studied and had the highest impact on these events. 45% of cases were related to the cause of the accident. Other cases after training have had almost the same effect on the occurrence of events. Each of the cases accounted for 11% of the causes of the accidents.  Conclusion: Beta tripod technique is currently one of the best methods for tracing the roots of accidents. The results also indicate that effective measures in the normal time phase, i.e. employing more talented people, conducting training at the beginning of employment, and upstream perspective, i.e. operator coordination with hardware and methods of implementation in the phase of ideas and thinking and design will greatly prevent accidents.

Comparison of error tree analysis and TRIPOD BETA in accident analysis of a power plant industry using hierarchical analysis

Introduction: Due to the importance and necessity of accident analysis, it is necessary to use the proper technique for precise accident analysis and provide corrective and preventive measures to prevent an accident's recurrence. Materials and Methods: In this descriptive-analytical paper, the most important criteria for investigating and selecting accident investigation and analysis techniques and selecting the best accident analysis method were identified in critical industrial accidents in the construction phase, were identified and analyzed. In this study, the most important criteria for selecting an accident analysis method were identified using previous research and gathering expert opinions. Then, two critical power plant accidents were analyzed using TRIPOD BETA and FTA accident analysis methods. Then the pairwise comparisons matrix was formed based on the strengths and weaknesses of the models. Finally, the prioritization of these two methods was done using the hierarchical analysis decision-making method.  Results: In this paper, seven key factors, model realism, model descriptive, systematic modeling, run time, required training courses, ability to quantify, and visibility of events, were identified as the most important criteria for selecting an incident analysis method. Conclusion: The TRIPOD BETA method has been introduced as an optimal method for investigating specific events due to its capabilities.

Comparison of efficiency of engineering and administrative interventions on risk level of occupational hazards in task of emergency nurses in yazd Shahid Rahnamoon hospital

Introduction: Emergency ward nurses are exposed to occupational hazards. Job Safety Analysis (JSA) is a way to identify and assess job-related risks and provide control strategies to reduce risks. The purpose of this study was to evaluate Job Safety Analysis and compare the efficacy of control (engineering and administrative) interventions in emergency nursing. Materials and Methods: This was an interventional study performed to assess the risk by Job Safety Analysis (JSA) in three groups of nurses working in emergrncy ward of Shahid Rahnemoon hospital in 2019. First, the initial risk assessment code (pre-intervention) estimated, then the engineering and administrative controls were implemented and the secondary risk assessment code (after intervention) was calculated after three months. Results: According to the results of the study، risk of musculoskeletal disorders with risk score of 20, was identified as the highest risk in all three emergency nursing groups, also mean risk assessment code for the occupational hazards in nurses was calculated which was in the unacceptable risk range and reached an acceptable level after performing administrative and engineering interventions. Conclusion: Results of this study showed that the implementation of engineering and administrative interventions had a positive effect on reducing the mean risk assessment code, also risk assessment code for occupational hazards reduced to almost the same amount with the implementation of each engineering and administrative intervention. This indicates similar role for these interventions in reducing the risk level.

Determining optimal risk assessment model in construction projects (Case study: steel plant construction project

Introduction: Identifying occupational hazards and managing occupational safety and health risks has been the most important mission and responsibility of the health and safety management system in organizations and adopting coded plans to achieve this is the key to continuously improving this system and promoting it. The aim of the present study was to determine the optimal risk assessment methodology in development projects. Materials and Methods: This was a descriptive-analytic research In this research, using previous research studies and collecting expert opinions, the most important criteria for selecting a specific risk assessment methodology, and then using one of the three most-used techniques is an important activity in the steel making industry and risk assessment. Then, the decision matrix is based on the strengths and weaknesses of the models. The prioritization of these three methods is done using the hierarchical analysis decision method. Results: In this paper, five key factors, the degree of application in identifying hazards, usability in different stages of risk assessment, reliability, ease of use, and training needs and costs, are identified as the most important criteria for choosing a risk assessment technique and the FMEA method was considered as the best  Risk Assessment Method. Conclusion: FMEA methodhas been introduced with regard to its capabilities as an optimal risk assessment method for contruction projects.

Efficient de-noising of high-resolution fMRI using local and sub-band information

BACKGROUND

High-resolution fMRI, useful for accurate brain mapping, suffers from low functional sensitivity at a reasonable acquisition time. Conventional smoothing techniques although reduce the noise and boost the sensitivity, but degrade the spatial resolution of fMRI.

NEW METHODS

We propose a novel spatial de-noising technique to increase sensitivity while preserving the boundaries of active regions in the high-resolution fMRI. A modified version of PCA that utilizes adjacent voxels information (LPCA) is first suggested for de-noising. This technique is then further empowered by its application to wavelet sub-bands (WLPCA).

RESULTS

Proposed techniques were assessed on both simulated and experimental data. Identifiablity index was calculated for evaluation of the denoising on the simulated data. Maximum and mean z-scores along with LAE and SSIM were reported on experimental data for two presented techniques as well as Guassian smoothing. WLPCA outperformed other techniques in Identifiablity index, for simulation, and in preserving maximum z-score, for experimental study.

COMPARISON WITH EXISTING METHODS

The presented technique was developed to simultaneously suppress the noise and preserve the boundaries of active areas against leakage. For first aim, its achievable mean z-score was compared to conventional Gaussian. For second aim, its maximum z-score was compared to that of no-smoothing. While Gaussian and no-smoothing can work fine with only one measure, WLPCA was able to improve both measures concurrently.

CONCLUSIONS

The local PCA based methods, and in particular WLPCA, is an effective noise reduction step that preserves the spatial resolution by preventing activity leakage of high-resolution fMRI data.

The effect of prior endoscopic correction of vesicoureteral reflux on open ureteral reimplantation: Surgical outcomes and costs

INTRODUCTION

Endoscopic injection of a bulking agent is a common first-line approach to the treatment of vesicoureteral reflux (VUR). While early outcomes are comparable to open ureteroneocystotomy, 5-25% of children will eventually develop recurrent reflux necessitating repeat injections or open ureteral reimplantation.

OBJECTIVE

To determine whether prior endoscopic injection of a bulking agent impacts outcomes of subsequent open ureteral reimplantation.

STUDY DESIGN

Using a retrospective cohort design, radiographic and clinical outcomes of open ureteral reimplantation were compared between patients with and without prior endoscopic correction of reflux. Surgical and hospitalization data were also compared between groups and a cost comparison was performed to assess differences in healthcare costs between the two cohorts. Units of analysis included total ureters or total patients. For certain variables, subanalysis of unilateral versus bilateral reimplantation was included.

RESULTS

A total of 258 patients underwent open reimplantation for VUR between 2007 and 2016 by five pediatric urologists. Final analysis (see Summary Table) included 192 patients with pre-operative and postoperative voiding cystourethrogram (VCUG) and follow-up data at a median 4.95 months. Among 317 reimplanted refluxing ureters, radiographic resolution was reached in 26/27 (96.3%) patients with and 279/290 (96.2%) without prior endoscopic treatment (P = 0.981). Clinical success was achieved in 17/17 (100%) patients with and 174/175 (99.4%) without prior endoscopic treatment (P = 0.755). There were no statistically significant differences between duration of surgery or length of hospital stay. There were no statistically significant differences between total charges, total costs, and operating room (OR) costs between groups.

DISCUSSION

This study indicated that prior endoscopic injection of a bulking agent did not impact the outcomes or costs of subsequent open ureteroneocystotomy. While prior studies have demonstrated tissue changes associated with injection of a bulking agent, these did not seem to significantly impact the difficulty of later open surgery or the success rates compared to patients who proceeded directly to open correction of reflux.

CONCLUSION

Open ureteral reimplantation for recurrent VUR after failed endoscopic injection of a bulking agent was safe and effective, with comparable outcomes and costs to open surgery in patients without prior endoscopic correction.

Comparison and Evaluation of Different Treatment Plans with IFRT Field and 6 and 18 MV Energies in Hodgkin's Lymphoma Involvement Neck and Mediastinum

BACKGROUND

Radiotherapy with large mantle field is an effective technique in increasing the risk of secondary cancers among HL (Hodgkin Lymphoma) patients; therefore, it is essential to choose an effective treatment field including the least medical conditions in radiotherapy.

OBJECTIVE

The present study aimed to plan separate fields for neck and mediastinum using various energies, to compare dose distribution with MLC and to block field formation.

MATERIALS AND METHODS

In this study, 3D conformal treatments, Siemens Oncor accelerator equipped with multi-leaf collimator (MLC) were performed to create anterior-posterior fields. CT-scan data of 18 female patients with neck and mediastinal involvement was imported in TIGRT treatment planning system, and then treatment plans were introduced.

RESULTS AND CONCLUSION

Using treatment plan 1, photon 6 MV in neck weighting 1 from interior, 0.5 from posterior, photon 18MV in mediastinum weighting 1 from interior and 0.5 from posterior, it was shown that regarding the common treatment plan used with photon 6 MV, mean dose delivered to breast, lung, esophagus and larynx reduced 6, 7, 41 and 10 percent, respectively and uniformity index improved by 10 percent. Using block compared to MLC in all treatment plans offered improved average dose in all organs under study. To protect breast and lung while using MLC and block in the first treatment plan seemed to be more appropriate; however, using blocks in comparison to MLC increased delivered mean dose in all organs under study. Using separate fields with Pb blocks, though, showed smaller increase.

Subject-based discriminative sparse representation model for detection of concealed information

BACKGROUND AND OBJECTIVES

The use of machine learning approaches in concealed information test (CIT) plays a key role in the progress of this neurophysiological field. In this paper, we presented a new machine learning method for CIT in which each subject is considered independent of the others. The main goal of this study is to adapt the discriminative sparse models to be applicable for subject-based concealed information test.

METHODS

In order to provide sufficient discriminability between guilty and innocent subjects, we introduced a novel discriminative sparse representation model and its appropriate learning methods. For evaluation of the method forty-four subjects participated in a mock crime scenario and their EEG data were recorded. As the model input, in this study the recurrence plot features were extracted from single trial data of different stimuli. Then the extracted feature vectors were reduced using statistical dependency method. The reduced feature vector went through the proposed subject-based sparse model in which the discrimination power of sparse code and reconstruction error were applied simultaneously.

RESULTS

Experimental results showed that the proposed approach achieved better performance than other competing discriminative sparse models. The classification accuracy, sensitivity and specificity of the presented sparsity-based method were about 93%, 91% and 95% respectively.

CONCLUSIONS

Using the EEG data of a single subject in response to different stimuli types and with the aid of the proposed discriminative sparse representation model, one can distinguish guilty subjects from innocent ones. Indeed, this property eliminates the necessity of several subject EEG data in model learning and decision making for a specific subject.

Results of combination chemotherapy and radiation therapy in non-metastatic gastric cancer in Yazd--Iran

BACKGROUND

Gastric cancer is the first cause of cancer death in Iran. Most of the patients are diagnosed in advanced stages and survival rate is low. The aim of this study was to evaluate the survival rate of patients with gastric and gastroesophageal junction adenocarcinoma receiving combination chemotherapy and radiation therapy in Iran.

MATERIALS AND METHODS

This study was conducted on 53 patients with gastric or gastroesophageal junction adenocarcinoma referring to Shahid Ramezanzadeh Radiation Oncology Center between 2004 and 2010. All patients underwent surgical operation, chemotherapy, and radiotherapy. Data contained in patients' records were extracted and follow-up was conducted through telephone contacts. To analyze the data, Kaplan Meier curves, and SPSS software were employed.

RESULTS

Seventeen (32.1%) patients were female and 36 (67.9%) were male. Mean age was 58.32 years. In 14 patients (26.9%) no lymph node was resected or reported by the pathologist. In 29 patients (54.7%) one to six lymph nodes were found, and in10 patients (18.9%) seven lymph nodes or more were detected. In two patients, (3.77%) more than 15 lymph nodes were resected. Surgical staging was impossible for 16 patients (30.2%). Mean survival was 50.9 months and median survival was 51 months. 3,5 and 7 year survival rates were 73%, 36%, and 18% respectively. None of the variables had a significant relation to survival.

CONCLUSIONS

Despite inadequate surgery, the survival rate in our study is one of the best one reported in our country. We think this advantage may be due to poly drug chemotherapy and sequential radiation therapy.

Clinicopathologic characteristics and outcome of childhood and adolescent Ewing's sarcoma in center of Iran

BACKGROUND

Ewing's sarcoma family is a group of small round cells tumors. The aim of this study is to evaluate clinicopathologic characteristics and outcome of Ewing's sarcoma in children and adolescents in Yazd, Iran.

MATERIALS AND METHODS

All patients under 19 years with documented pathology of Ewing's sarcoma family tumor who referred to Shahid Ramazanzadeh Radiotherapy center between 2002 to 2010 were enrolled in this retrospective study. Overall survival and disease free survival and prognostic factors were evaluated.

RESULTS

Among approximately 80,000 patients who referred to Shahid Sadoughi pathology department, over an 8-year period, the total number of patients with Ewing sarcoma was 32, of which, 18 cases were under the age 19 . The mean age was 13.72 years. Five patients (27.8%) had metastatic disease at the time of diagnosis. Complete response had been achieved in 8 (44.4%) of the patients. Local recurrence occurred in 4 (22.2%) of the patients. During the follow up 13 (72.2%) of the patients showed metastases. The mean overall survival was 34.79 months (95% CI: 22.27-47.32) .One, two, four and five year survival was 72%, 39%, 25% and 17% respectively. Complete remission occurred in 10 patients (63.6%). A trend of better overall survival was found in these patients (p=0. 55). When the brain and bone metastases occurred, the overall survival decreased significantly (p=0. 003 ).

CONCLUSIONS

The overall survival rate of Ewing's sarcoma is very low in comparison with other parts of the world.

Triterpenes from Euphorbia spinidens with immunomodulatory activity

Dried aceton-chloroform extract of aerial parts of Euphorbia spinidens Bornm. ex Prokh. endemic to Iran, yielded two new triterpenoids, lup-20(29)-ene-33, 28 diol commonly known as betulin and (3β,23E)-Cycloarta-23-ene-3,25-diol. The structures of the isolated compounds were elucidated by 13C- and 1H-NMR as well as 2D-NMR, IR and by the aid of mass fragmentation pattern. In phagocyte chemiluminescence assay, different concentrations of compounds were incubated with the human whole blood in triplicate and the chemiluminescence activity of phagocytic cells were measured by using serum opsonized zymosan and luminol. For lymphocyte proliferation assay, peripheral human blood lymphocytes were incubated with different concentrations of the test compound in supplemented Roswell Park Memorial Institute (RPMI) 1640 medium along with 5.0 μg/ml phytohemagglutinin (PHA) at 37°C in CO2 environment for 72 h and proliferation level was determined by Beta-scintillation counter. In phagocyte chemiluminescence assay, betulin showed moderate inhibitory effect on the oxidative burst in the neutrophils, while addition of betulin triterpene was able to stimulate the proliferation of the phytohemagglutinin (PHA) treated human peripheral blood lymphocytes (hPBLs).

Low voltage cycling of programmable metallization cell memory devices

Future nanoscale memory technologies must ultimately be able to operate at power supply voltages in the order of 0.6 V or less. We have demonstrated in this work that it is possible to utilize symmetric program-erase (P-E) cycling for Ag/Ag-Ge-S/W programmable metallization cell devices at voltages below 0.6 V and still maintain an OFF/ON resistance ratio well in excess or 10 over a wide range of program and erase currents (0.27, 1.6, 55 and 220 µA) as set by a series resistance. The distributions of resistance values for 10(4) P-E cycles indicate that the margins between the highest on- and lowest off-state resistances are sufficient for unambiguous differentiation in all but the lowest current case in which there is some overlap. In addition, there is no substantial change in switching speed for up to 1.5 × 10(6) P-E operations, the maximum number of cycles attempted in this study.

Ossifying fibromyxoid tumour: a rare soft tissue tumour of intermediate malignancy

Ossifying fibromyxoid tumours (OFTs) are uncommon soft tissue tumours. A 73-year-old male presented with a painless exophytic mass located in the left scapular area which was identified 1 year earlier. An incisional biopsy was performed and microscopic features were compatible with OFT. Radiologic evaluation revealed multiple pulmonary metastasis. Although many cases persue an indolent biologic behaviour, local recurrence and metastasis have been reported and long-term follow-up should be considered.

Nevoid malignant melanoma in an albino woman

Albinism is a disorder of hypopigmentation affecting the skin, hair and eyes. Ultraviolet light induced cutaneous tumours are common in patients with albinism due to reduced or absent protection from melanin, with squamous cell carcinoma being the most common. Although non-melanomatous skin cancers are more frequent in patients with albinism, dysplastic nevi and melanoma present a greater diagnostic challenge in this group because of their hypopigmented appearance. Here the authors report a case of nevoid malignant melanoma in a patient who had type 1A oculocutaneous albinism.

Association of breast artery calcification with coronary artery disease and carotid intima-media thickness in premenopausal women

ABSTRACT This study investigated whether breast arterial calcification (BAC) has an association with coronary artery diseases (CAD) in young premenopausal women and evaluated the association of BAC with carotid intima-media thickness and standard CAD risk factors. Among 84 premenopausal women aged < 55 years who were referred for coronary angiography, 34 (40.5%) had abnormal angiographic findings and 6 (7.1%) showed BAC in their mammograms. The body mass index of patients with BAC was significantly higher than those without BAC. BAC had no significant association with angiography-confirmed CAD.

N-linked glycosylation sites determine HERG channel surface membrane expression

1. Long QT syndrome (LQT) is an electrophysiological disorder that can lead to sudden death from cardiac arrhythmias. One form of LQT has been attributed to mutations in the human ether-a-go-go-related gene (HERG) that encodes a voltage-gated cardiac K+ channel. While a recent report indicates that LQT in some patients is associated with a mutation of HERG at a consensus extracellular N-linked glycosylation site (N629), earlier studies failed to identify a role for N-linked glycosylation in the functional expression of voltage-gated K+ channels. In this study we used pharmacological agents and site-directed mutagenesis to assess the contribution of N-linked glycosylation to the surface localization of HERG channels. 2. Tunicamycin, an inhibitor of N-linked glycosylation, blocked normal surface membrane expression of a HERG-green fluorescent protein (GFP) fusion protein (HERGGFP) transiently expressed in human embryonic kidney (HEK 293) cells imaged with confocal microscopy. 3. Immunoblot analysis revealed that N-glycosidase F shifted the molecular mass of HERGGFP, stably expressed in HEK 293 cells, indicating the presence of N-linked carbohydrate moieties. Mutations at each of the two putative extracellular N-linked glycosylation sites (N598Q and N629Q) led to a perinuclear subcellular localization of HERGGFP stably expressed in HEK 293 cells, with no surface membrane expression. Furthermore, patch clamp analysis revealed that there was a virtual absence of HERG current in the N-glycosylation mutants. 4. Taken together, these results strongly suggest that N-linked glycosylation is required for surface membrane expression of HERG. These findings may provide insight into a mechanism responsible for LQT2 due to N-linked glycosylation-related mutations of HERG.