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Radiofrequency ablation (RFA) is a non-invasive image-guided procedure where tumors are heated in the body with electrical current. RFA procedures are commonly indicated for patients with limited local disease or who are not surgical candidates. Current methods of RFA use multiple cords and wires that ergonomically complicate the procedure and present the risk of cutting or shorting the circuit if they are damaged. A wireless RFA technique based on electromagnetic induction is presented in this paper. The transmitting and receiving coils were coupled to resonate at the same frequency to ensure the highest power output. The receiving coil was connected to two insulated electrodes on a catheter, which allowed the current to flow to the targeted tissue. The prototype system was tested with ex-vivo bovine tissue, which has similar thermal and electrical properties to human tissue. The setup can monitor the received power, efficiency, temperature, and ablation zone during ablation procedures. The maximum received power was 15 W, and the average maximum efficiency was 63.27%. The novel system was also able to ablate up to a 2 cm ablation zone in non-perfused tissue. This proof of concept for performing RFA wirelessly with electromagnetic induction may merit further optimization.
Diet has direct and indirect effects on health through inflammation and the gut microbiome. We investigated total dietary inflammatory potential via the literature-derived index (Dietary Inflammatory Index (DII®)) with gut microbiota diversity, composition and function. In cancer-free patient volunteers initially approached at colonoscopy and healthy volunteers recruited from the medical centre community, we assessed 16S ribosomal DNA in all subjects who provided dietary assessments and stool samples (n 101) and the gut metagenome in a subset of patients with residual fasting blood samples (n 34). Associations of energy-adjusted DII scores with microbial diversity and composition were examined using linear regression, permutational multivariate ANOVA and linear discriminant analysis. Spearman correlation was used to evaluate associations of species and pathways with DII and circulating inflammatory markers. Across DII levels, α- and β-diversity did not significantly differ; however, Ruminococcus torques, Eubacterium nodatum, Acidaminococcus intestini and Clostridium leptum were more abundant in the most pro-inflammatory diet group, while Akkermansia muciniphila was enriched in the most anti-inflammatory diet group. With adjustment for age and BMI, R. torques, E. nodatum and A. intestini remained significantly associated with a more pro-inflammatory diet. In the metagenomic and fasting blood subset, A. intestini was correlated with circulating plasminogen activator inhibitor-1, a pro-inflammatory marker (rho = 0·40), but no associations remained significant upon correction for multiple testing. An index reflecting overall inflammatory potential of the diet was associated with specific microbes, but not overall diversity of the gut microbiome in our study. Findings from this preliminary study warrant further research in larger samples and prospective cohorts.
There are two major forms of long-term depression (LTD) of synaptic transmission in the central nervous system, which require activation of either N-methyl-D-aspartate receptors (NMDARs) or metabotropic glutamate receptors (mGluRs). In synapses in the perirhinal cortex we have directly compared the Ca2+ signalling mechanisms involved in NMDAR-LTD and mGluR-LTD. Whilst both forms of LTD involve Ca2+ release from intracellular stores the Ca2+ sensors involved are different; NMDAR-LTD involves calmodulin, whilst mGluR-LTD involves the neuronal Ca2+ sensor (NCS) protein NCS-1. In addition, there is a specific requirement for IP3 and PKC as well as protein interacting with C-kinase (PICK-1) in mGluR-LTD. NCS-1 binds directly to PICK1, via its BAR domain, in a Ca2+-dependent manner. Furthermore, the NCS-1-PICK1 association is stimulated by activation of mGluRs, but not NMDARs, and introduction of a PICK1 BAR domain fusion protein specifically blocks mGluR-LTD. Thus, NCS-1 is a component of a novel mechanism involved in mGluR-LTD.
Excavations at Shichengzi, the probable location of ancient Shule, have revealed diverse burial practices suggesting a population with varied cultural backgrounds. Together with archaeobotanical evidence, this indicates a community of agro-pastoralists and Han Dynasty migrants using diverse cropping patterns to attain self-sufficiency. The project raises interesting questions about the impact of migrations on the identities of inhabitants.
Single-crystalline gallium arsenide (GaAs) grown by various techniques can exhibit hillock defects on the surface when sub-optimal growth conditions are employed. The defects act as nonradiative recombination centers and limit solar cell performance. In this paper, we applied near-field transport imaging to study hillock defects in a GaAs thin film. On the same defects, we also performed near-field cathodoluminescence, standard cathodoluminescence, electron-backscattered diffraction, transmission electron microscopy, and energy-dispersive X-ray spectrometry. We found that the luminescence intensity around the hillock area is two orders of magnitude lower than on the area without hillock defects in the millimeter region, and the excess carrier diffusion length is degraded by at least a factor of five with significant local variation. The optical and transport properties are affected over a significantly larger region than the observed topography and crystallographic and chemical compositions associated with the defect.
Despite established clinical associations among major depression (MD), alcohol dependence (AD), and alcohol consumption (AC), the nature of the causal relationship between them is not completely understood. We leveraged genome-wide data from the Psychiatric Genomics Consortium (PGC) and UK Biobank to test for the presence of shared genetic mechanisms and causal relationships among MD, AD, and AC.
Linkage disequilibrium score regression and Mendelian randomization (MR) were performed using genome-wide data from the PGC (MD: 135 458 cases and 344 901 controls; AD: 10 206 cases and 28 480 controls) and UK Biobank (AC-frequency: 438 308 individuals; AC-quantity: 307 098 individuals).
Positive genetic correlation was observed between MD and AD (rgMD−AD = + 0.47, P = 6.6 × 10−10). AC-quantity showed positive genetic correlation with both AD (rgAD−AC quantity = + 0.75, P = 1.8 × 10−14) and MD (rgMD−AC quantity = + 0.14, P = 2.9 × 10−7), while there was negative correlation of AC-frequency with MD (rgMD−AC frequency = −0.17, P = 1.5 × 10−10) and a non-significant result with AD. MR analyses confirmed the presence of pleiotropy among these four traits. However, the MD-AD results reflect a mediated-pleiotropy mechanism (i.e. causal relationship) with an effect of MD on AD (beta = 0.28, P = 1.29 × 10−6). There was no evidence for reverse causation.
This study supports a causal role for genetic liability of MD on AD based on genetic datasets including thousands of individuals. Understanding mechanisms underlying MD-AD comorbidity addresses important public health concerns and has the potential to facilitate prevention and intervention efforts.
Background. Frequency and quantity of alcohol consumption are metrics commonly used to measure alcohol consumption behaviors. Epidemiological studies indicate that these alcohol consumption measures are differentially associated with (mental) health outcomes and socioeconomic status (SES). The current study aims to elucidate to what extent genetic risk factors are shared between frequency and quantity of alcohol consumption, and how these alcohol consumption measures are genetically associated with four broad phenotypic categories: (i) SES; (ii) substance use disorders; (iii) other psychiatric disorders; and (iv) psychological/personality traits.
Methods. Genome-Wide Association analyses were conducted to test genetic associations with alcohol consumption frequency (N = 438 308) and alcohol consumption quantity (N = 307 098 regular alcohol drinkers) within UK Biobank. For the other phenotypes, we used genome-wide association studies summary statistics. Genetic correlations (rg) between the alcohol measures and other phenotypes were estimated using LD score regression.
Results. We found a substantial genetic correlation between the frequency and quantity of alcohol consumption (rg = 0.52). Nevertheless, both measures consistently showed opposite genetic correlations with SES traits, and many substance use, psychiatric, and psychological/personality traits. High alcohol consumption frequency was genetically associated with high SES and low risk of substance use disorders and other psychiatric disorders, whereas the opposite applies for high alcohol consumption quantity.
Conclusions. Although the frequency and quantity of alcohol consumption show substantial genetic overlap, they consistently show opposite patterns of genetic associations with SES-related phenotypes. Future studies should carefully consider the potential influence of SES on the shared genetic etiology between alcohol and adverse (mental) health outcomes.
Microorganisms are the most abundant organisms on Earth, and microbial abundance records preserved in ice cores have been connected to records of environmental change. As an alternative to high resolution abundance records, which can be difficult to recover, we used culture-dependent and culture-independent methods to examine bacteria in glacier ice from the Tibetan Plateau (TP). We recovered a total of 887 bacterial isolates from ice cores of up to 164 m in depth retrieved from seven glaciers, located across the TP. These isolates were related to 53 genera in the Actinobacteria, Firmicutes, Bacteroidetes, and Proteobacteria, with 13 major genera accounting for 78% of isolates. Most of the genera were common across the geographic region covered by our sampling, but there were differences in the genera recovered from different depths in the ice, with the deepest portions of the ice cores dominated by a single genus (Sporosarcina). Because microorganisms deposited on glaciers must survive atmospheric transport under a range of temperatures, temperature tolerance should be an important survival mechanism. We tested isolate growth across a range of temperatures (0–35 °C), and found psychrotolerance to be common. Together, our results show that ice depth, and by extension age, are characterized by different types of microorganisms, providing new information about microbial records in ice.
A point-prevalence study of antimicrobial use among inpatients at 5 public hospitals in Sri Lanka revealed that 54.6% were receiving antimicrobials: 43.1% in medical wards, 68.0% in surgical wards, and 97.6% in intensive care wards. Amoxicillin-clavulanate was most commonly used for major indications. Among patients receiving antimicrobials, 31.0% received potentially inappropriate therapy.
This study was designed to explore the association between undernutrition in the growth period and cardiovascular risk factors in a middle-aged Chinese population. A total of 1756 subjects, aged 45–60 years, were invited to participate in the Hefei Nutrition and Health Study and divided into three groups according to their self-reported animal food intake in the growth period. Group 1, Group 2 and Group 3 were defined as undernutrition, nutritional improvement and the good nutrition group, respectively. In the three groups, the subjects in Groups 1 and 2 had more oil and salt intake (P<0.001), and less eggs and milk intake (P<0.001), when compared with the subjects in Group 3. After adjusting for age, education, smoking status and other confounding factors, it was found that male participants who experienced nutritional improvement before age 18 had higher risk of hypertension [odds ratio (OR)=1.68; 95% confidence intervals (CI): 1.05, 2.69] than those with good nutrition, and female participants with undernutrition (OR=1.52; 95% CI: 1.01, 2.29) and nutritional improvement (OR=1.68; 95% CI: 1.04, 2.69) before age 18 had a higher risk of hypertension than those with good nutrition. For diabetes, obesity, hypercholesterolemia and hypertriglyceridemia, our results did not found difference among the three groups both in male and female. Our findings indicated that nutritional deficiency in childhood was associated with bad dietary behaviors and a significantly increased risk of hypertension in middle age. Therefore, early adequate nutrition is very important for the prevention of non-communicable diseases later.
Mastery of strengthening strategies to achieve high-capacity anodes for lithium-ion batteries can shed light on understanding the nature of diffusion-induced stress and offer an approach to use submicro-sized materials with an ultrahigh capacity for large-scale batteries. Here, we report solute strengthening in a series of silicon (Si)–germanium (Ge) alloys. When the larger solute atom (Ge) is added to the solvent atoms (Si), a compressive stress is generated in the vicinity of Ge atoms. This local stress field interacts with resident dislocations and subsequently impedes their motion to increase the yield stress in the alloys. The addition of Ge into Si substantially improves the capacity retention, particularly in Si0.50Ge0.50, aligning with literature reports that the Si/Ge alloy showed a maximum yield stress in Si0.50Ge0.50. In situ X-ray diffraction studies on the Si0.50Ge0.50 electrode show that the phase change undergoes three subsequent steps during the lithiation process: removal of surface oxide layer, formation of cluster-size Lix(Si,Ge), and formation of crystalline Li15(Si,Ge)4. Furthermore, the lithiation process starts from higher index facets, i.e., (220) and (311), then through the low index facet (111), suggesting the orientation-dependence of the lithiation process in the Si0.50Ge0.50 electrode.
The stability of a shale containing smectite with different exchangeable cations (Na+, Ca2+) was improved using optimum solutions containing polyether amine (PA), poly-alcohol (PO) or KCl. Two types of shale samples with Na+ and Ca2+ as the main exchangeable cations, respectively, were used and the optimized solutions were determined using X-ray diffraction (XRD), an adsorption test, an oedometer swelling test, and an immersion test. The use of KCl prevented intercalation of PA or PO and maintained the stability of the Na-smectite-bearing shale. PA or PO adsorption reduced water adsorption sites on the clay layer, and K+ reduced hydration of exchangeable Na+, resulting in good shale stability in mixed solutions of KCl+PA, and KCl+PO. More stable shale was achieved in KCl+ PA mixed solution, whereas in the KCl+ PO solution the transport of water or solute molecules in the shale was reduced. In the shale containing mainly Ca-smectite, PA, PO and KCl maintained shale stability when applied separately or in common, as PA or PO cannot exchange Ca2+ in the smectite interlayer. As a result, PA or PO should be used together with KCl during drilling in shale formations containing Na-smectite, whereas in shales with Ca-smectite, PA, PO or KCl may be used separately.
The effect of transverse magnetic fields on surface high-harmonic generation in intense laser–solid interactions is investigated. It is shown that the longitudinal motion of electrons can be coupled with the transverse motion via the magnetic fields, which lead to even-order harmonics under normal laser incidence. The dependence of the coupling efficiency and hence even harmonic generation with preplasma scale length and magnetic field strength are presented based upon particle-in-cell simulations. When the magnetic field is parallel to the laser electric field, the spectral intensity of the second harmonic is proportional to the magnetic field strength in a wide range up to 160 MG, while the situation with the magnetic field perpendicular to the laser electric field is more complicated. The second harmonic generation due to the magnetic field also tends to increase with the plasma density scale lengths, which is different from the high-harmonic generation by the oscillating mirror mechanism. With the increase of the laser spot size from a laser wavelength λL, both the magnetic field-induced harmonics and oscillating mirror high harmonics tend to increase first and then become saturated after 3λL. The magnetic field-induced second harmonic may be used to evaluate large self-generated magnetic fields developed near the critical density region and the preplasma conditions.