Active shimming for a 25 T NMR superconducting magnet by spectrum convergence method.

In the design of ultrahigh field nuclear magnetic resonance (NMR) superconducting magnets, it typically requires a high homogeneous magnetic field in the diameter of spherical volume (DSV) to obtain high spectrum resolution. However, shimming technique presents challenges due to the magnet bore space limitations, as accurate measurement of magnetic field distribution is very difficult, especially for customized micro-bore magnets. In this study, we introduced an active shimming method that utilized iterative adjustment of shim coil currents to improve the magnetic field homogeneity based on the full width at half maximum (FWHM) of the spectrum. The proposed method can determine the optimal set of currents for shim coils, effectively enhancing spatial field homogeneity by converging the FWHM. Experimental validation on a 25 T NMR superconducting magnet demonstrated the efficacy of the proposed method. Specifically, the active shimming method improved the field homogeneity of a 10 mm DSV from 7.09 ppm to 2.27 ppm with only four shim coils, providing a superior magnetic field environment for solid NMR and further magnetic resonance imaging (MRI) experiment. Furthermore, the proposed method can be promoted to more customized micro-bore magnets that require high magnetic field homogeneity.

Analysis of Ileal Atresia from Prenatal Ultrasound to Postoperative Follow-up: Two Case Reports.

BACKGROUND: Congenital ileal atresia is a rare neonatal disease, the most common type of intestinal malformation in newborns, and one of the most common causes of congenital intestinal obstruction. It can cause various digestive system symptoms, including abdominal distension, vomiting, abnormal bowel movements, etc. In severe cases, it can be life-threatening. A prenatal ultrasound examination can assist clinical diagnosis of congenital ileal atresia, and those with a clear prenatal diagnosis should undergo surgical treatment after birth. CASE PRESENTATION: We have, herein, reported two cases of congenital ileal atresia, both of which showed fetal intestinal dilation (>7mm) and excessive amniotic fluid on prenatal ultrasound. Both newborns underwent surgical treatment after delivery and were confirmed to have congenital ileal atresia during surgery. Due to the different prenatal ultrasound manifestations of the two patients, they were divided into two different subtypes based on intraoperative manifestations. We observed significant differences in the prognosis of the two patients after surgery. CONCLUSION: Accurately locating and classifying ileal atresia using prenatal ultrasound is challenging; however, it plays an effective role in disease progression, gestational assessment, and prognosis. Accurately identifying intestinal diseases and/or the location of lesion sites through direct and indirect ultrasound findings in the fetal abdominal cavity is an important research direction for prenatal ultrasound.

Suction detection and suction suppression of centrifugal blood pump based on the FFT-GAPSO-LSTM model and speed modulation.

Centrifugal blood pumps are important devices used to treat heart failure. However, they are prone to high-risk suction events that pose a threat to human health when operating at high speeds. To address these issues, a normal suction detection method and a suction suppression method based on the FFT-GAPSO-LSTM model and speed modulation were proposed. The innovation of this suction detection method lies in the application of the genetic particle swarm optimisation (GAPSO) and the fast Fourier transform (FFT) feature extraction method to the long-term and short-term memory (LSTM) model, thereby improving the accuracy of suction detection. After detecting signs of suction, the suction suppression method designed in this study based on variable-speed modulation immediately takes effect, enabling the centrifugal blood pump to quickly return to its normal state by controlling the speed. The suction detection method was divided into four steps. First, a mathematical model of the coupling of the cardiovascular system and the centrifugal blood pump was established, and a real-time blood flow curve was obtained through model simulation. Second, the signal was preprocessed by adding Gaussian white noise and low-pass filtering to make the blood flow signal close to actual working conditions while retaining the original characteristics. Subsequently, through fast Fourier transform (FFT) analysis of the processed curve, the spectral characteristics that can characterise the working state of the centrifugal blood pump were extracted. Finally, the parameters of the LSTM model were optimised using the GAPSO, and the improved LSTM model was used to train and test the blood flow spectrum feature set. The results show that the suction detection method of the FFT-GAPSO-LSTM model can effectively detect whether centrifugal blood pump suction occurs and has certain advantages over other methods. In addition, the simulation results of the suction suppression were excellent and could effectively suppress the occurrence of suction. These results provide a reference for the design of centrifugal blood pump control systems.

Passive shimming for the 9.4 T whole-body MRI superconducting magnet.

A superconducting magnet with a warm-bore size of 800 mm and a center magnetic field of 9.4 T for the whole-body magnetic resonance imaging (MRI) system was developed in IEECAS, China. To achieve a highly homogeneous magnetic field over the 400 mm diameter of spherical volume (DSV), both active shimming and passive shimming techniques were employed. This paper mainly focuses on the implementation of passive shimming for the 9.4 T MRI magnet system. After four iterations, we were able to achieve peak-to-peak and root mean square field homogeneities over the DSV at 3.05 and 0.94 ppm, respectively. In addition, this paper analyzes the electromagnetic forces and system errors of passive shimming for ultra-high fields, providing valuable insights into MRI magnet engineering.

A sliding mode control of the bearingless permanent magnet slice motor for the blood pump based on the GAPSO.

In this paper, we proposed a sliding mode control method for the bearingless permanent magnet slice motor for the blood pump based on the genetic particle swarm algorithm, which aims to solve the problems of strong coupling, strong interference, nonlinearity and uncertainty. Firstly, the mathematical model of rotor torque and suspension force of the bearingless permanent magnet slice motor is established. Secondly, the structure of sliding mode observer is deduced by designing sliding mode surface and control law. And, the performance parameters of sliding mode observer are optimized by the genetic particle swarm optimization algorithm. Thirdly, electromagnetic torque and suspension force control under this control method is studied by Simulink. Finally, the control method is applied to the control of the blood flow of the blood pump, and the rotation speed can effectively control the blood flow. The results indicate that compared with PID control and traditional sliding mode control methods, the sliding mode control method optimized by the genetic particle swarm optimization algorithm greatly improves the control performance of bearingless permanent magnet slice motor. The results show that the blood flow can meet expectations with a small error, which fully meets the blood perfusion requirements of the blood pump.

On the passive shimming of a 7 T whole-body MRI superconducting magnet: Implementation with minimized ferromagnetic materials usage and operable magnetic force control.

BACKGROUND: Magnetic field shimming of the magnet is a routine practice in a magnetic resonance imaging (MRI) system. For clinically-used 1.5 T or 3 T MRI superconducting magnets, it is generally straightforward to achieve desired magnetic field uniformity with the passive shim technique. In comparison, superconducting shims with higher shimming efficiency are usually introduced in combination with passive shimming to satisfy the higher magnetic field uniformity requirement for ultrahigh field magnets (≥7 Tesla). However, superconducting shim usually involves a complex winding structure and low-temperature environment, bringing considerable engineering challenges and extra costs in practice. PURPOSE: In this study, we aimed to improve the passive shimming method that can incorporate the unique electromagnetic properties of ultrahigh-field MRI magnets and is thus more effective for field corrections at 7T and above. METHODS: In this work, we propose a dedicated passive shimming strategy for a 7 T whole-body MRI superconducting magnet. In this method, the iron usage and magnetic force due to the iron-field interaction are strictly managed to ensure a shim tray insert is operable by manpower (without specially designed tools). RESULTS: To validate the proposed shimming strategy, a shimming experiment was implemented on a 7 T/800 mm superconducting magnet. Alternating with the odd and even shim trays in our two-round operation, the magnetic field inhomogeneity was successfully corrected from 85.36 to 7.91 ppm, achieving the magnetic field quality elevation of more than one order of magnitude. CONCLUSION: The experimental results indicated that the proposed electromagnetic technology is expected to be effective for developing ultrahigh-field MRI instruments.

Zwitterionic coating assisted by dopamine with metal-phenolic networks loaded on titanium with improved biocompatibility and antibacterial property for artificial heart.

Introduction: Titanium (Ti) and Ti-based alloy materials are commonly used to develop artificial hearts. To prevent bacterial infections and thrombus in patients with implanted artificial hearts, long-term prophylactic antibiotics and anti-thrombotic drugs are required, and this may lead to health complications. Therefore, the development of optimized antibacterial and antifouling surfaces for Ti-based substrate is especially critical when designing artificial heart implants. Methods: In this study, polydopamine and poly-(sulfobetaine methacrylate) polymers were co-deposited to form a coating on the surface of Ti substrate, a process initiated by Cu2+ metal ions. The mechanism for the fabrication of the coating was investigated by coating thickness measurements as well as Ultraviolet-visible and X-ray Photoelectron (XPS) spectroscopy. Characterization of the coating was observed by optical imaging, scanning electron microscope (SEM), XPS, atomic force microscope (AFM), water contact angle and film thickness. In addition, antibacterial property of the coating was tested using Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) as model strains, while the material biocompatibility was assessed by the antiplatelet adhesion test using platelet-rich plasma and in vitro cytotoxicity tests using human umbilical vein endothelial cells and red blood cells. Results and discussion: Optical imaging, SEM, XPS, AFM, water contact angle, and film thickness tests demonstrated that the coating was successfully deposited on the Ti substrate surface. The biocompatibility and antibacterial assays showed that the developed surface holds great potential for improving the antibacterial and antiplatelet adhesion properties of Ti-based heart implants.

SOX7 modulates the progression of hepatoblastoma through the regulation of Wnt/ß-catenin signaling pathway.

Aims: Hepatoblastoma (HB) was reported as the frequently diagnosed primary hepatic malignant tumor among children. No reports have shown the function of SOX7 and its relationship with the Wnt/ß-catenin pathway in HB. Materials and Methods: SOX7 and factors related to Wnt/ß-catenin pathway were detected using reverse transcription-quantitative polymerase chain reaction (RT-PCR) and Western blotting. MTT 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium and flow cytometry were used to detect HB cell proliferation and apoptosis. The transwell assay uses cell invasion. Results: In this study, RT-PCR, Western blotting, and immunohistochemistry results indicated that the expression of SOX7 was significantly reduced in HB tissues compared with adjacent noncancerous tissues, while the ß-catenin was significantly increased in HB tissues compared with adjacent noncancerous tissues. There were significant differences in the PRETEXT stage and tumor metastasis between patients with low expression and high expression of SOX7. Moreover, it was found that the overexpression of SOX7 and inhibiting Wnt/ß-catenin pathway significantly reduced the cell proliferation and invasion, while the cell apoptosis was significantly increased compared with the control group. Conclusions: This study shows that SOX7 was downexpressed in HB tumor tissues. Moreover, ex vivo experiments indicated that SOX7 was related to ß-catenin and regulated the progression of HB cells.

Prognostic significance and tumor-immune infiltration of mTOR in clear cell renal cell carcinoma.

Mammalian target of rapamycin (mTOR), a serine/threonine kinase involved in cell proliferation, survival, metabolism and immunity, was reportedly activated in various cancers. However, the clinical role of mTOR in renal cell carcinoma (RCC) is controversial. Here we detected the expression and prognosis of total mTOR and phosphorylated mTOR (p-mTOR) in clear cell RCC (ccRCC) patients, and explored the interactions between mTOR and immune infiltrates in ccRCC. The protein level of mTOR and p-mTOR was determined by western blotting (WB), and their expression was evaluated in 145 ccRCC and 13 non-tumor specimens by immunohistochemistry (IHC). The relationship to immune infiltration of mTOR was further investigated using TIMER and TISIDB databases, respectively. WB demonstrated the ratio of p-mTOR to mTOR was higher in ccRCC than adjacent specimens (n = 3), and IHC analysis elucidated that p-mTOR expression was positively correlated with tumor size, stage and metastasis status, and negatively correlated with cancer-specific survival (CSS). In univariate analysis, high grade, large tumor, advanced stage, metastasis, and high p-mTOR expression were recognized as prognostic factors of poorer CSS, and multivariate survival analysis elucidated that tumor stage, p-mTOR and metastasis were of prognostic value for CSS in ccRCC patients. Further TIMER and TISIDB analyses uncovered that mTOR gene expression was significantly associated with numerous immune cells and immunoinhibitors in patients with ccRCC. Collectively, these findings revealed p-mTOR was identified as an independent predictor of poor survival, and mTOR was associated with tumor immune infiltrates in ccRCC patients, which validated mTOR could be implicated in the initiation and progression of ccRCC.

The effects of vasoactive intestinal peptide on RANKL-induced osteoclast formation.

BACKGROUND: Congenital pseudarthrosis of the tibia is a rare disease characterized by an imbalance in bone remodeling. Vasoactive intestinal peptide (VIP) has been proven to modulate bone resorption and the formation of osteoclasts. This study aimed to explore the effects of VIP on the homeostasis of bone metabolism in diverse in vitro systems. METHODS: Bone marrow-derived macrophages (BMMs) were differentiated into tartrate-resistant acid phosphatase-positive cells through incubation with receptor activator of nuclear factor κB ligand (RANKL) and macrophage colony-stimulating factor (M-CSF). In vitro resorption pit detection was carried out to assess the effects of VIP on osteoclastic activity. Rat osteosarcoma cell line ROS 17/2.8 was cultured alone or co-cultured with rat BMMs in the presence or absence of VIP at various concentrations. The expression levels of RANKL, RANK, OPG, NF-κB, IL-6, ERK, CAII, and GAPDH were determined by qRT-PCR and WB assay. RESULTS: VIP was observed to repress osteoclast differentiation without affecting the number of osteoclast precursor cells. Furthermore, the modulation of the RANKL/osteoprotegerin (OPG), nuclear factor-κB (NF-κB), and extracellular signal-regulated kinase (ERK) signaling pathways were involved in the inhibitive influence of VIP upon bone erosion. Additionally, VIP affected the expression levels of osteoclastic factors including RANKL, OPG, and interleukin-6 in osteoblast cells. Furthermore, the expression levels of RANKL and RANK were increased, while OPG expression was reduced after treatment with VIP in the co-culture of ROS 17/2.8 and rat BMMs. ERK and NF-κB signal pathways were demonstrated to be involved in the effect of VIP in the co-culture system. CONCLUSIONS: VIP plays a critical role in bone remodeling and might serve as a potential target in the development of treatments for congenital pseudarthrosis of the tibia.

Expression and prognostic significance of fatty acid synthase in clear cell renal cell carcinoma.

Fatty acid synthase (FASN), a key enzyme essential for fatty acid (FA) synthesis, was reportedly implicated in the initiation and progression of various cancers. However, the clinical significance of FASN in renal cell carcinoma (RCC) has not been fully elucidated yet. Here we compare the expression profile and evaluate the prognostic significance of FASN in clear cell RCC (ccRCC) patients. FASN expression was examined in 3 pairs ccRCC and their adjacent nontumor tissues by western blotting (WB) analysis, and its expression was assessed in 145 ccRCC and 13 nontumor tissues by immunohistochemistry (IHC) analysis with tissue microarrays (TMAs). The prognosis of FASN was further investigated in large-scale database using LinkedOmics (n = 537) and The Cancer Protein Atlas (TCPA, n = 445), respectively. WB detected higher FASN expression in ccRCC than normal tissues, then IHC analysis revealed that FASN expression was positively associated with histological grade, pathological stage, tumor size and metastasis status, and negatively associated with cancer-specific survival (CSS). Univariate survival analysis demonstrated that high grade, advanced stage, large tumor, metastasis, and high FASN expression were significantly associated with a shorter CSS, and multivariate analysis revealed tumor grade, stage, metastasis and FASN were identified as independent predictors for CSS in patients with ccRCC. Further LinkedOmics and TCPA analyses confirmed that high FASN expression was correlated with a poorer overall survival (OS) of ccRCC. Collectively, these findings demonstrated FASN could be a poor prognostic factor in ccRCC patients, which indicated that FA synthesis might be implicated in the tumorigenesis and progression of ccRCC.

Prognostic significance of PI3K/AKT/ mTOR signaling pathway members in clear cell renal cell carcinoma.

BACKGROUND: Renal cell carcinoma (RCC) is a fatal disease, in which the PI3K/AKT/mTOR signaling pathway serves an important role in the tumorigenesis. Previous studies have reported the prognostic significance of PI3K/AKT/mTOR signaling pathway members in RCC; however, there is insufficient evidence to date to confirm this. Thus, the present study aimed to systematically investigate the prognostic roles of multiple PI3K/AKT/mTOR signaling proteins in clear cell RCC (ccRCC) using online large-scale databases. METHODS: The mRNA expression profiles of PI3K/AKT/mTOR signaling pathway proteins PTEN, PIK3CA, PIK3CB, PIK3CD, PIK3CG, AKT1, AKT2, AKT3 and mTOR were investigated using the Gene Expression Profiling Interactive Analysis (GEPIA) and Oncomine databases, and the protein expression levels of PI3K, AKT and mTOR were detected using western blotting (WB) analysis. In addition, the correlation between mRNA or protein expression levels and the prognostic significance was analyzed using the Kaplan-Meier (K-M) plotter (n = 530), the Human Protein Atlas (HPA; n = 528) and The Cancer Protein Atlas (TCPA; n = 445) databases. RESULTS: The GEPIA revealed that the mRNA expression of major PI3K/AKT/mTOR pathway members, including PTEN, PIK3CA, PIK3CB, AKT1, AKT2 and AKT3, were negatively correlated with ccRCC stages (P < 0.05), though most of their mRNA and protein expression levels were notsignificantly different between ccRCC and normal tissues using GEPIA, Oncomine and WB analyses (P < 0.05). Meanwhile, using the K-M plotter and HPA prognostic analysis, it was found that the mRNA expression levels of the majority of the PI3K/AKT/mTOR signaling pathway members, including PTEN, PIK3CA, PIK3CB, PIK3CG, AKT3 and mTOR were positively correlated with overall survival (OS), whereas PIK3CD mRNA expression was negatively correlated with OS (P < 0.05). Furthermore, TCPA prognostic analysis observed that several of the key molecules of the PI3K/AKT/mTOR signaling pathway [PTEN, p-AKT (S473) and p-mTOR (S2448)] were also positively correlated with OS in patients with ccRCC (P < 0.05). In conclusion, the present study suggested that several members of the PI3K/AKT/mTOR signaling pathway, especially PTEN, may be favorable prognostic factors in ccRCC, which indicated that the PI3K/AKT/mTOR signaling pathway may be implicated in ccRCC initiation and progression.

Highly Shielded Gradient Coil Design for a Superconducting Planar MRI System.

In a planar, superconducting magnetic resonance imaging (MRI) system, the gradient assembly is placed into the groove of the SC magnet. Conventional gradient coil design method considers the shielding of pole face only, but neglects the surrounding metal structures at the coil side, thus leading to large stray field leakage and resulting in serious eddy current artefact. A novel coil shielding method was proposed in this work by a full consideration of the stray fields on the pole face and also the coil ends. The gradient coil design exemplification of a 0.7T planar superconducting MRI system was presented. In the new design, the maximum stray field at the surface of the ambient structure was reduced more than six times for the transverse coils and around four times for the longitudinal coil. The highly shielded gradient coil also produced linear gradient fields (<5%) over the imaging volume.

The mRNA Expression Signature and Prognostic Analysis of Multiple Fatty Acid Metabolic Enzymes in Clear Cell Renal Cell Carcinoma.

Renal cell carcinoma (RCC) is a metabolic disease, and accumulating evidences indicate significant alterations in the cellular metabolism, especial aerobic glycolysis and glutamine metabolism, in RCC. However, fatty acid (FA) metabolism has received less attention, and the mRNA expression pattern and prognostic role of FA metabolic enzymes in clear cell RCC (ccRCC) have not been carefully examined. In the current study, we first investigated the mRNA expression profiles of multiple FA metabolic enzymes, i.e., ACLY, ACC, FASN, SCD, CPT1A, HADHA, HADHB, and ACAT1, in 42 ccRCC and 33 normal kidney tissues using the Oncomine database, validated their mRNA expression profiles using GEPIA resource, then evaluated and validated the prognostic significance of these metabolic enzymes in 530 ccRCC patients using Kaplan-Meier plotter and GEPIA analyses respectively. The Oncomine and GEPIA confirmed higher ACLY, SCD, and lower ACAT1 mRNA expression in ccRCC than normal tissues (P<0.05). And further prognostic analysis displayed that overexpression of the some FA anabolic enzymes (FASN) was correlated to poor overall survival (OS), while overexpression of the FA catabolic enzymes (CPT1A, HADHA, HADHB, and ACAT1) was correlated to favorable OS in ccRCC patients. In conclusion, multiple FA metabolic enzymes, such as FASN, HADHA, and ACAT1, were potential prognostic markers of ccRCC, which implied alterations in FA metabolism might be involved in ccRCC tumorigenesis and progression.

Tesseral superconducting shim coil design with quasi-saddle geometry for use in high-field magnet system.

Superconducting shim coils are frequently used in high-field magnetic resonance imaging or nuclear magnetic resonance system for their high sensitivity and shimming strength. The design of superconducting shim coils is based on the spherical harmonic decomposition, and each shim coil is normally dedicated for correcting one specific harmonic component. Conventional superconducting shim coil with a saddle loop has observable winding error near the corner, which gives rise to arc transformation when winding layer by layer. Simulation analysis shows that the arc corner transformation will induce the magnetic field deviation by more than double of the theoretical design ±1%, which may be up to ±3% after real winding. An improved shim coil design method with a quasisaddle geometry was proposed to correct the winding error. With the consideration of both the rounded corner of the saddle loop and the arc side, the new design offers the magnetic field deviation within ±1%. In addition to reducing the winding error, the proposed design also facilitates the winding process.

HADHA overexpression disrupts lipid metabolism and inhibits tumor growth in clear cell renal cell carcinoma.

Hydroxyacyl-CoA dehydrogenase alpha subunit (HADHA) is a key lipid metabolic enzyme with a novel role in carcinogenesis. We previously reported that HADHA, a prognostic marker, was downregulated in clear cell renal cell carcinoma (ccRCC). Herein, the tumor inhibitory role of HADHA overexpression in ccRCC was investigated further. The quantitative proteomic analysis displayed that a total of 1293 and 1293 proteins were identified in HADHA overexpressed 786-O-hadha and vector-transfected control 786-O-vc cells, respectively, and 206 proteins were found to be up- or downregulated. PANTHER, OmicsNet, STRING, and DAVID tools were utilized on the dysregulated proteins in order to elucidate multiple metabolic pathways (especial lipid metabolism) and lipid metabolism-related proteins (e.g. ACAT1, ACLY). The dysregulation of the lipid metabolic enzymes, ACAT1, ACLY, CYB5R3 and FASN, were confirmed by Western blotting. Further assays demonstrated that HADHA overexpression significantly inhibited cell growth, induced cell apoptosis, and decreased the formation of cytoplasmic lipid droplets (LDs); moreover, it also inhibited tumor growth and lessened the formation of LDs in xenografted mouse. Collectively, these data revealed that HADHA overexpression disrupted lipid metabolism and inhibited tumor growth, which shed light on HADHA as a potential therapeutic target for clinical intervention of ccRCC.

Prognostic Value of MTV, SUVmax and the T/N Ratio of PET/CT in Patients with Glioma: A Systematic Review and Meta-Analysis.

Background: In the past decade, positron emission tomography/computed tomography (PET/CT) has become an important imaging tool for clinical assessment of tumor patients. Our meta-analysis aimed to compare the predictive value of PET/CT parameters regard to overall survival (OS) and progression-free survival (PFS) outcomes in glioma. Methods: Relevant articles were systematically searched in PMC, PubMed, EMBASE and WEB of science. Studies involving the prognostic roles of PET/CT parameters with OS and PFS in glioma patients were evaluated. The impact of metabolic tumor volume (MTV), maximal standard uptake value (SUVmax), and the ratio of uptake in tumor to normal (T/N ratio) on survival was measured by calculating combined hazard ratios (HRs) and 95% confidence intervals (CIs). Results: A total of 32 articles with 1715 patients were included. The combined HRs of higher MTV, higher SUVmax and higher T/N ratio for OS were 1.14 (95% CI: 0.98-1.32, P heterogeneity<0.001), 1.69 (95% CI: 1.18-2.41, P heterogeneity<0.001) and 1.68 (95% CI: 1.40-2.01, P heterogeneity< 0.001), respectively. Regarding PFS, the combined HRs were 1.04 (95% CI: 0.97-1.11, P heterogeneity=0.002) with higher MTV, 1.45 (95% CI: 1.11-1.90, P heterogeneity<0.001) with higher SUVmax and 2.07 (95% CI: 1.45-2.95, P heterogeneity<0.001) with higher T/N ratio. Results remained similar in the sub-group analyses. Conclusion: PET/CT parameters T/N ratio may be a significant prognostic factor in patients with glioma. Evidence of SUVmax and MTV needed more large-scale studies performed to validate. PET/CT scan could be a promising technique to provide prognostic information for these patients.

A Dichotomization Winding Scheme on a Novel Asymmetric Head Gradient Coil Design With an Improved Force and Torque Balance.

The head gradient coil is advantageous for brain imaging compared to the conventional whole-body gradient coil. It is usually asymmetrically designed for the accommodation of human shoulders. The asymmetric head coil has a specific issue associated with an unbalanced force/torque that requires minimization for imaging applications. This paper will improve the force and torque balance solution and propose a dichotomization winding scheme to augment the coil slew rate. A square force and torque optimization enables the available balanced asymmetric head gradient coil design, with a force and torque approaching the minimum level. Subsequently, two practical parallel connection winding schemes were quantitatively analyzed and evaluated. The results show that the proposed dichotomization winding scheme can increase the slew rate to almost twice that of the conventional winding counterpart, without obviously influencing the magnetic field performance.

Evaluation and prognostic significance of manganese superoxide dismutase in clear cell renal cell carcinoma.

The antioxidant enzyme manganese superoxide dismutase (MnSOD) is up-regulated in renal cell carcinoma (RCC) and has been implicated in multiple stages of RCC tumorigenesis and progression. However, the prognostic significance of MnSOD in RCC has not been fully elucidated. This study aimed to investigate the expression profile of MnSOD in clear cell RCC (ccRCC) tissues and evaluate the clinical significance of this enzyme in ccRCC patients. MnSOD mRNA was assessed in 42 ccRCC and 33 normal kidney tissues using the Oncomine database, and its protein was detected in 145 ccRCCs and 3 normal tissues by immunohistochemistry staining. The Oncomine database confirmed higher MnSOD mRNA expression in ccRCC than in normal tissues, and immunohistochemistry analysis revealed that MnSOD protein expression was inversely associated with pathologic grade, clinical stage, tumor size, M status, and cancer-specific survival. In addition, univariate survival analysis demonstrated that high-grade, late-stage, large tumors, stage M1, and low MnSOD expression were associated with a poorer prognosis for cancer-specific survival, and further multivariate analysis revealed that tumor grade, stage, M1 stage, and MnSOD were identified as independent prognostic factors for cancer-specific survival in patients with ccRCC. Collectively, these findings imply that MnSOD is a promising prognostic marker in ccRCC and implies that oxidative stress might be involved in the tumorigenesis and progression of ccRCC.

Breastfeeding and the risk of childhood Hodgkin lymphoma: a systematic review and meta-analysis.

PURPOSE: Numerous observational epidemiological studies have evaluated associations between breastfeeding and the risk of childhood Hodgkin lymphoma; however, the existing results are inconsistent. We therefore conducted a systematic review and meta-analysis. METHODS: Medical literature was searched in the Pubmed and Embase databases to identify all English-language relevant studies up to April 10, 2013. Reference lists were thereafter hand-searched for additional articles. Studies that reported relative risk ratios (RRs) or odds ratios (ORs) with 95% confidence intervals (CIs) were included. This meta-analysis was conducted in accordance with the guidelines for the meta-analysis of observational studies in epidemiology. RESULTS: We finally included 10 case-control studies in our meta-analysis, involving 1,618 childhood Hodgkin lymphoma cases and 8,181 controls. Overall, we did found a borderline significant association between breastfeeding and reduced risk of childhood Hodgkin lymphoma comparing ever breastfed children to never breastfed children (pooled OR =0.79; 95%CI, 0.58-1.08; P=0.13), with limited evidence for between-study heterogeneity (P =0.12, I2 = 35.70%). CONCLUSION: There is limited evidence for an inverse association between breastfeeding and risk of childhood Hodgkin lymphoma.