[Constructing an early-warning model for mortality risk in heat stroke patients based on Fisher discriminant analysis]

Objective: To establish an early warning model to assess the mortality risk of patients with heat stroke disease. Methods: The case data of patients diagnosed with heat stroke disease admitted to the comprehensive ICU of Shanshan County from January 2016 to December 2020 were selected. According to the short-term outcome (28 days) of patients, they were divided into death group (20 cases) and survival group (53 cases) . The relevant indicators with statistically significant differences between groups within 24 hours after admission were selected. By drawing the subject work curve (ROC) and calculating the area under the curve, the relevant indicators with the area under the curve greater than 0.7 were selected, Fisher discriminant analysis was used to establish an assessment model for the death risk of heat stroke disease. The data of heat stroke patients from January 1, 2021 to December 2022 in the comprehensive ICU of Shanshan County were collected for external verification. Results There were significant differences in age, cystatin C, procalcitonin, platelet count, CKMB, CK, CREA, PT, TT, APTT, heart rate, respiratory rate and GLS score among the groups. Cystatin C, CKMB, CREA, PT, TT, heart rate AUC area at admission was greater than 0.7. Fisher analysis method is used to build a functional model. Results: The diagnostic sensitivity, specificity and AUC area of the functional model were 95%, 83% and 0.937 respectively. The external validation results showed that the accuracy of predicting survival group was 85.71%, the accuracy of predicting death group was 88.89%. Conclusion: The early warning model of heat stroke death constructed by ROC curve analysis and Fisher discriminant analysis can provide objective reference for early intervention of heat stroke.

Stabilizing Supersaturation with Extreme Grain Refinement in Spinodal Aluminum Alloys

Supersaturated solid solutions can be formed in alloys from various non-equilibrium processes, but stabilizing the metastable phases against decomposition is challenging, particularly the spinodal decomposition that occurs via chemical fluctuations without energy barriers to nucleation. In this work, it is found that spinodal decomposition in supersaturated Al(Zn) solid solutions can be inhibited with straining-induced extreme grain refinement. For the refined supersaturated grains at the nanoscale, their spinodal decomposition is obviously resisted by the relaxed grain boundaries and reduced lattice defects. As grains are refined below 10 nm the decomposition is completely inhibited, in which atomic diffusion is blocked by the stable Schwarz crystal structure with vacancy-free grains. Extreme grain refinement offers a general approach to stabilize supersaturated phases with broadened compositional windows for property modulation of alloys.

Bioactivity and mechanism of action of sanguinarine and its derivatives in the past 10 years

Sanguinarine is a quaternary ammonium benzophenanthine alkaloid found in traditional herbs such as Chelidonium, Corydalis, Sanguinarum, and Borovula. It has been proven to possess broad-spectrum biological activities, such as antitumor, anti-inflammatory, antiosteoporosis, neuroprotective, and antipathogenic microorganism activities. In this paper, recent progress on the biological activity and mechanism of action of sanguinarine and its derivatives over the past ten years is reviewed. The results showed that the biological activities of hematarginine and its derivatives are related mainly to the JAK/STAT, PI3K/Akt/mTOR, NF-κB, TGF-β, MAPK and Wnt/β-catenin signaling pathways. The limitations of using sanguinarine in clinical application are also discussed, and the research prospects of this subject are outlined. In general, sanguinarine, a natural medicine, has many pharmacological effects, but its toxicity and safety in clinical application still need to be further studied. This review provides useful information for the development of sanguinarine-based bioactive agents.

Vegetation-fire feedbacks increase subtropical wildfire risk in scrubland and reduce it in forests

Climate dictates wildfire activity around the world. But East and Southeast Asia are an apparent exception as fire-activity variation there is unrelated to climatic variables. In subtropical China, fire activity decreased by 80% between 2003 and 2020 amid increased fire risks globally. Here, we assessed the fire regime, vegetation structure, fuel flammability and their interactions across subtropical Hubei, China. We show that tree basal area (TBA) and fuel flammability explained 60% of fire-frequency variance. Fire frequency and fuel flammability, in turn, explained 90% of TBA variance. These results reveal a novel system of scrubland-forest stabilized by vegetation-fire feedbacks. Frequent fires promote the persistence of derelict scrubland through positive vegetation-fire feedbacks; in forest, vegetation-fire feedbacks are negative and suppress fire. Thus, we attribute the decrease in wildfire activity to reforestation programs that concurrently increase forest coverage and foster negative vegetation-fire feedbacks that suppress wildfire.

The impact of acute-phase reaction on mortality and re-fracture after zoledronic acid in hospitalized elderly osteoporotic fracture patients

This study involving 674 elderly osteoporotic fracture (OPF) patients undergoing orthopedic surgery investigated the long-term outcomes of acute phase reaction (APR) after initial zoledronic acid (ZOL). Those who had an APR had a 97% higher risk of mortality and a 73% lower rate of re-fracture than patients who did not.

INTRODUCTION

Annual infusion of ZOL efficiently decreases the risk of fracture. A temporary APR, consisting of flu-like symptoms, myalgia, and fever, is frequently observed within 3 days after the first dose. This work aimed to identify whether the occurrence of APR after initial ZOL infusion is a reliable indicator of drug efficacy for mortality and re-fracture in elderly OPF patients undergoing orthopedic surgery.

METHODS

This retrospectively observed work was constructed on a database prospectively collected from the Osteoporotic Fracture Registry System of a tertiary level A hospital in China. Six hundred seventy-four patients 50 years old or older with newly identified hip/morphological vertebral OPF who received ZOL for the first time after orthopedic surgery were included in the final analysis. APR was identified as a maximum axillary body temperature greater than 37.3 °C for the first 3 days after ZOL infusion. We utilized models of multivariate Cox proportional hazards to compare the risk of all-cause mortality in OPF patients with APR (APR+) and without APR (APR-). Competing risks regression analysis was used to examine the association between the occurrence of APR and re-fracture when mortality was taken into account.

RESULTS

In a fully adjusted Cox proportional hazards model, APR+ patients had a significantly higher risk of death than APR- patients with a hazard ratio [HR] 1.97 (95% CI, 1.09-3.56; P-value = 0.02). Furthermore, in an adjusted competing risk regression analysis, APR+ patients had a significantly reduced risk of re-fracture compared with APR- patients with a sub-distribution HR, 0.27 (95% CI, 0.11-0.70; P-value = 0.007).

CONCLUSIONS

Our findings suggested a potential association between the occurrence of APR and increased mortality risk. An initial dose of ZOL following orthopedic surgery was found to be protective against re-fracture in older patients with OPFs.

[Efficacy and safety of bendamustine-rituximab combination therapy for newly diagnosed indolent B-cell non-Hodgkin's lymphoma and elderly mantle cell lymphoma: a multi-center prospective phase II clinical trial in China]

Objectives: This study aimed to assess the efficacy and safety of bendamustine in combination with rituximab (BR regimen) for the treatment of newly diagnosed indolent B-cell non-Hodgkin's lymphoma (B-iNHL) and elderly mantle cell lymphoma (eMCL) . Methods: From December 1, 2020 to September 10, 2022, a multi-center prospective study was conducted across ten Grade A tertiary hospitals in Shandong Province, China. The BR regimen was administered to evaluate its efficacy and safety in newly diagnosed B-iNHL and eMCL patients, and all completed at least four cycles of induction therapy. Results: The 72 enrolled patients with B-iNHL or MCL were aged 24-74 years, with a median age of 55 years. Eastern Cooperative Oncology Group (ECOG) performance status scores of 0-1 were observed in 76.4% of patients, while 23.6% had scores of 2. Disease distribution included follicular lymphoma (FL) (51.4% ), marginal zone lymphoma (MZL) (33.3% ), eMCL (11.1% ), and the unknown subtype (4.2% ). According to the Ann Arbor staging system, 16.7% and 65.3% of patients were diagnosed with stage Ⅲ and stage Ⅳ lymphomas, respectively. Following four cycles of BR induction therapy, the overall response rate was 98.6%, with a complete response (CR) rate of 83.3% and a partial response (PR) rate of 15.3%. Only one eMCL patient experienced disease progression during treatment, and only one FL patient experienced a relapse. Even when evaluated using CT alone, the CR rate was 63.9%, considering the differences between PET/CT and CT assessments. The median follow-up duration was 11 months (range: 4-22), with a PFS rate of 96.8% and an OS rate of 100.0%. The main hematologic adverse reactions included grade 3-4 leukopenia (27.8%, with febrile neutropenia observed in 8.3% of patients), grade 3-4 lymphopenia (23.6% ), grade 3-4 anemia (5.6% ), and grade 3-4 thrombocytopenia (4.2% ). The main non-hematologic adverse reactions such as fatigue, nausea/vomiting, rash, and infections occurred in less than 20.0% of patients. Conclusion: Within the scope of this clinical trial conducted in China, the BR regimen demonstrated efficacy and safety in treating newly diagnosed B-iNHL and eMCL patients.

Inhibiting creep in nanograined alloys with stable grain boundary networks

Creep, the time-dependent deformation of materials stressed below the yield strength, is responsible for a great number of component failures at high temperatures. Because grain boundaries (GBs) in materials usually facilitate diffusional processes in creep, eliminating GBs is a primary approach to resisting high-temperature creep in metals, such as in single-crystal superalloy turbo blades. We report a different strategy to inhibiting creep by use of stable GB networks. Plastic deformation triggered structural relaxation of high-density GBs in nanograined single-phased nickel-cobalt-chromium alloys, forming networks of stable GBs interlocked with abundant twin boundaries. The stable GB networks effectively inhibit diffusional creep processes at high temperatures. We obtained an unprecedented creep resistance, with creep rates of ~10 –7 per second under gigapascal stress at 700°C (~61% melting point), outperforming that of conventional superalloys.

Chronic insulin resistance deteriorates cardiac mitochondrial quality control in a mouse model of SEC-NAFLD-IR

Background

Insulin resistance and nonalcoholic fatty liver disease (NAFLD) both relate to cardiovascular mortality. Using a mouse model of chronic lipid overload and secondary-NAFLD-induced insulin resistance (SEC-NAFLD-IR), we recently deciphered that SEC-NAFLD-IR already at young age provoked myocardial lipotoxicity with reduced mitochondrial efficiency and increased vulnerability to cardiac ischemia. However, long-term consequences of SEC-NAFLD-IR remain elusive.

Purpose

Here we aimed to elucidate the impact of long-term SEC-NAFLD-IR on multiple mitochondrial quality control (mQC) mechanisms in the heart and its consequences for cardiac function.

Methods

We studied 36 SEC-NAFLD-IR mice (72-week-old). For mechanistic experiments, we applied palmitate-induced insulin resistant murine HL-1 cells. Cardiac mitochondrial dynamics were measured via quantification of mitochondrial morphology and expression of mitochondrial fusion and fission factors (Opa1, Drp1, Fis1, Mfn 1 & 2). Mitophagy level was evaluated via immunofluorescence and protein expression of key mitophagy-related genes (Parkin, NIX, LC3). Mitochondrial biogenesis and mass were examined via quantitation of PGC-1α expression, mtDNA and citrate synthase activity.

Results

72-week-old SEC-NAFLD-IR mice exhibited 21% (p=0.001) and 32% (p<0.001) higher body weight and heart weight compared with controls. Along with elevated oxidative stress, hepatic lipid accumulation and inflammation, 6h-fasted SEC-NAFLD-IR mice were characterized by increased plasma glucose, insulin and cholesterol. SEC-NAFLD-IR mice displayed a cardiac phenotype with 21% higher left ventricular mass (normalized to body weight, p<0.001) and 6% lower ejection fraction compared to controls (73.5% SEM 0.90 vs 69.4% SEM 1.65, p=0.04). We found several advantageous mQC mechanisms suppressed in aged SEC-NAFLD-IR mice including long form OPA1-mediated mitochondrial fusion, Parkin- and NIX-mediated mitophagy. Likewise, mitochondrial biogenesis was suppressed in the aged insulin-resistant heart, which was connected to a 65% downregulation of PGC-1α1 expression (p=0.01). Interestingly, downregulation of cardiac PGC-1α1 in aged SEC-NAFLD-IR mice coincided with upregulation of PARIS, indicating the crucial participation of the Parkin/PARIS pathway in mQC of the insulin-resistant heart. In addition, induction of insulin resistance in murine HL-1 cardiomyocytes also led to increased mitochondrial fragmentation and decreased PGC-1α1 expression.

Conclusion

This study demonstrated that regulation of mitochondrial network and turnover is hampered by SEC-NAFLD-IR in the hearts of aged mice, which may contribute to hypertrophy and cardiac dysfunction in insulin resistance.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Collaborative Research Centre 1116 (German Research Foundation)

Microplastics, potential threat to patients with lung diseases

Air pollution is one of the major risk factors for lung disease. Microplastics are a ubiquitous environmental pollutant, both indoors and in outdoor air. Microplastics have also been found in human lung tissue and sputum. However, there is a paucity of information on the effects and mechanisms of microplastics on lung disease. In this mini-review, we reviewed the possible mechanisms by which air microplastics' exposure affects lung disease and, at the same time, pointed out the limitations of current studies.

A Novel Mechanical Frequency Tuning Method Based on Mass-Stiffness Decoupling for MEMS Gyroscopes

MEMS gyroscopes play an important role in inertial navigation measurements, which mainly works in n = 2 mode. However, mode matching is the basis for high-precision detection, which can improve the sensitivity, resolution, and signal-to-noise ratio of the gyroscopes. An initial frequency split is inevitably generated during the manufacturing process. There are two methods to eliminate the frequency split and to achieve mode matching for the gyroscopes, which are electrostatic tuning and mechanical trimming, respectively. In this paper, we report a novel ring MEMS resonator and a novel method of mechanical frequency tuning. The most prominent characteristic of the resonator is that 16 raised mass blocks are increased in the circumferential positions of the ring uniformly. This structural design can achieve mass-stiffness decoupling, which means that punching holes on the mass blocks only affects the mass distribution but the stiffness is almost unchanged for the resonator. We verify the mass-stiffness decoupling by way of comparing the simulation with the conventional resonator. In addition, we put up an online tuning platform based on a femtosecond laser and reduce a resonator’s frequency split from 23.3 Hz to 0.4 Hz, which reveals that the frequency split is linearly related to the removed mass. These findings will have a referential significance for other transducers.

Experimental Evidence of Intrinsic Current Generation by Turbulence in Stationary Tokamak Plasmas

High-β_{θe} (a ratio of the electron thermal pressure to the poloidal magnetic pressure) steady-state long-pulse plasmas with steep central electron temperature gradient are achieved in the Experimental Advanced Superconducting Tokamak. An intrinsic current is observed to be modulated by turbulence driven by the electron temperature gradient. This turbulent current is generated in the countercurrent direction and can reach a maximum ratio of 25% of the bootstrap current. Gyrokinetic simulations and experimental observations indicate that the turbulence is the electron temperature gradient mode (ETG). The dominant mechanism for the turbulent current generation is due to the divergence of ETG-driven residual flux of current. Good agreement has been found between experiments and theory for the critical value of the electron temperature gradient triggering ETG and for the level of the turbulent current. The maximum values of turbulent current and electron temperature gradient lead to the destabilization of an m/n=1/1 kink mode, which by counteraction reduces the turbulence level (m and n are the poloidal and toroidal mode number, respectively). These observations suggest that the self-regulation system including turbulence, turbulent current, and kink mode is a contributing mechanism for sustaining the steady-state long-pulse high-β_{θe} regime.

Real-world circulating tumor DNA analysis depicts resistance mechanism and clonal evolution in ALK inhibitor-treated lung adenocarcinoma patients

Background

Sequential treatment with different generations of anaplastic lymphoma kinase (ALK) inhibitors have been widely applied to ALK-positive lung cancer; however, resistance mutations inevitably developed. Further characterization of ALK resistance mutations may provide key guidance to subsequent therapies. Here we explored the emergence of secondary ALK mutations during sequential ALK tyrosine kinase inhibitor (TKI) treatment in a real-world study of Chinese lung adenocarcinoma (ADC) patients.

Methods

A clinical-genomic database was queried for lung ADC patients with at least one ALK inhibitor treatment and at least one plasma sample collected following ALK inhibitor treatment. Targeted genome profiling was performed with a 139-gene panel in baseline tumor tissue and serial plasma samples of patients.

Results

A total of 116 patients met inclusion criteria. ALK G1202R was more common in patients with echinoderm microtubule-associated protein-like 4 (EML4)-ALK v3 fusion, whereas ALK L1196M was more common in v1. TP53 mutant patients were significantly associated with harboring multiple ALK resistance mutations (P = 0.03) and v3+/TP53 mutant patients had the highest rate of multiple ALK resistance mutations. The sequential use of ALK TKI led to an increased incidence of concurrent ALK mutations along the lines of therapies. Alectinib had a lower rate (9%) harboring ALK resistance mutation as first-line ALK TKI compared with crizotinib (36%). ALK compound mutations identified included ALK D1203N/L1196M, ALK G1202R/L1196M, and ALK G1202R/F1174C, which may be lorlatinib resistant. Using paired pretreatment and post-treatment samples, we identified several ALK-independent resistance-related genetic alterations, including PTPRD and CNKN2A/B loss, MYC, MYCN and KRAS amplification, and EGFR^19del.

Conclusions

Sequential postprogression plasma profiling revealed that increased lines of ALK inhibitors can accelerate the accumulation of ALK resistance mutations and may lead to treatment-refractory compound ALK mutations. The selection for optimal first-line TKI is very important to achieve a more efficacious long-term strategy and prevent the emergence of on-target resistance, which may provide guidance for clinical decision making.

•

ALK resistance mutations were differentially enriched in the setting of EML4-ALK v1/v3 and TP53 status.

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Serial liquid biopsies NGS depicted accumulation of multiple ALK secondary mutations during sequential ALK treatments.

•

Several lorlatinib-resistant ALK compound mutations and ALK-independent resistance genetic alterations were identified.

A Novel High-Speed and High-Accuracy Mathematical Modeling Method of Complex MEMS Resonator Structures Based on the Multilayer Perceptron Neural Network

MEMS resonators have become core devices in a large number of fields; however, due to their complex structures, the finite element analysis (FEA) method is still the main method for their theoretical analysis. The traditional finite element analysis method faces the disadvantages of large calculation amount and long simulation time, which limits the development of high-performance MEMS resonators. This paper demonstrates a high-speed and high-accuracy simulation tool based on the artificial neural network, where a multilayer perceptron (MLP) neural network model is constructed. The typical structural parameters of MEMS resonator are used as the input layer, and its performance indicators produced by the finite element analysis method are the output layer. After iteratively trained with 4000 samples, the cumulative error of the neural network decreases to 0.0017 and a prediction network model is obtained. Compared with the finite element analysis results, the structural accuracy error predicted by the neural network model can be controlled within 6%, but its runtime is shortened by 15,000 times. This high-speed and high-accuracy mathematical modeling method can effectively improve the analyzing efficiency and provide a promising tool for the design and optimization of different complex MEMS resonators, which exhibit remarkable accuracy and speed.

Formation of Stable Schwarz Crystals in Polycrystalline Copper at the Grain Size Limit

A prototype Schwarz crystal (SC) structure of dividing-space minimal grain boundaries (GBs) constrained by coherent twin boundaries (CTBs) was recently discovered in extremely fine-grained polycrystalline Cu. In this Letter, constraining effects of 3D CTB network on the formation and thermostability of SC are addressed via atomistic simulations. GB migration and evolution of CTB network trigger formation of SC diamond. CTB constraints are critical to generate GBs of zero mean curvature underlying vanishing capillary pressure, and to counterbalance the elastic driving forces of lattice. GB motion can be suppressed at temperatures close to the melting point with GB aperture down to 3 nm.

Detrimental effects of microplastic exposure on normal and asthmatic pulmonary physiology

Concerns that airborne microplastics (MP) may be detrimental to human health are rising. However, research on the effects of MP on the respiratory system are limited. We tested the effect of MP exposure on both normal and asthmatic pulmonary physiology in mice. We show that MP exposure caused pulmonary inflammatory cell infiltration, bronchoalveolar macrophage aggregation, increased TNF-α level in bronchoalveolar lavage fluid (BALF), and increased plasma IgG1 production in normal mice. MP exposure also affected asthma symptoms by increasing mucus production and inflammatory cell infiltration with notable macrophage aggregation. Further, we found co-labeling of macrophage markers with MP incorporating fluorescence, which indicates phagocytosis of the MP by macrophages. A comparative transcriptomic analysis showed that MP exposure altered clusters of genes related to immune response, cellular stress response, and programmed cell death. A bioinformatics analysis further uncovered the molecular mechanism whereby MP stimulated production of tumor necrosis factor and immunoglobulins to activate a group of transmembrane B-cell antigens, leading to the modulation of cellular stress and programmed cell death in the asthma model. In summary, we show that MP exposure had detrimental effects on the respiratory system in both healthy and asthmatic mice, which calls for urgent discourse and action to mitigate environmental microplastic pollutants.

Suppressing atomic diffusion with the Schwarz crystal structure in supersaturated Al-Mg alloys

High atomic diffusivity in metals enables substantial tuneability of their structure and properties by tailoring the diffusional processes, but this causes their customized properties to be unstable at elevated temperatures. Eliminating diffusive interfaces by fabricating single crystals or heavily alloying helps to address this issue but does not inhibit atomic diffusion at high homologous temperatures. We discovered that the Schwarz crystal structure was effective at suppressing atomic diffusion in a supersaturated aluminum-magnesium alloy with extremely fine grains. By forming these stable structures, diffusion-controlled intermetallic precipitation from the nanosized grains and their coarsening were inhibited up to the equilibrium melting temperature, around which the apparent across-boundary diffusivity was reduced by about seven orders of magnitude. Developing advanced engineering alloys using the Schwarz crystal structure may lead to useful properties for high-temperature applications.

Efficacy of annual zoledronic acid in initial percutaneous kyphoplasty patients with osteoporotic vertebral compression fractures: a 3-year follow-up study

This study investigated the efficacy of annual zoledronic acid (ZOL) administration against previously treated recompression vertebral fractures (RVF) and new vertebral fractures (NVF) in initial percutaneous kyphoplasty (PKP) patients with osteoporotic vertebral compression fractures (OVCF) over a 3-year follow-up period.

INTRODUCTION

Although PKP achieves a satisfactory outcome, previously treated RVF and NVF can limit its effectiveness. The annual infusion of ZOL over 3 years can improve fracture protection, particularly in the vertebrae. We hypothesized that ZOL can reduce the incidence of RVFs and/or NVFs, and improve the clinical outcomes of PKP.

METHODS

This was a placebo-controlled, double-blind prospective trial of 154 PKP patients (mean age: 70 years) with OVCFs. Patients were randomly assigned to receive a single infusion of ZOL (5 mg) or placebo (78 ZOL vs. 76 placebo) at 1 week, 12 months, and 24 months after surgery. Patients were followed-up for 36 months.

RESULTS

ZOL treatment lowered the risk of RVF by ~ 65% over the 36-month period when compared to placebo controls (6.41% in ZOL vs. 18.42% in placebo groups; relative risk, 0.35; 95% CI, 0.13 to 0.92). ZOL also reduced the risk of NVF by ~ 73% (3.85% in ZOL vs. 14.47% in placebo groups; relative risk, 0.27; 95% CI, 0.08 to 0.92). ZOL also significantly reduced the vertebral height lost rate (HLR) at 12, 24, and 36 months. ZOL also improved the visual analog scale (VAS), Oswestry disability index (ODI) scores, and bone mineral density (BMD).

CONCLUSION

Annual ZOL administration significantly lowers the risk of RVFs and NVFs, improving the clinical outcome of initial PKP in patients with OVCFs over a 3-year follow-up period.

TRIAL REGISTRATION

ChiCTR2000029307.

Postpartum bilateral sacral stress fracture without osteoporosis-a case report and literature review

PURPOSE

Sacral stress fractures are rare complications which can arise during pregnancy or in the early postpartum period. We report a case and discuss the findings of a confirmed postpartum sacral stress fracture in a 39-year-old multiparous woman and review previous case reports in the literature of sacral stress fracture related to pregnancy.

METHODS

A review of the literature was conducted to examine the main characteristics of sacral stress fractures related to pregnancy. The Ovid/Medline, Embase and Google Scholar databases were searched with the inclusion criteria: human studies, English language, intrapartum, postpartum (within 6 months of parturition), sacrum and stress fracture. Our exclusion criteria included pubic fractures, vertebral fractures and non-English articles. The search terms included "stress fracture", "postpartum", "pregnancy", "atraumatic" and the wildcard "sacr*". Thirty-four cases were found and summarised in Table 2.

RESULTS

A total of 65% of patients had onset of symptoms postpartum. Most patients did not have risk factors for sacral stress fractures including macrosomia, excessive pregnancy weight gain, heparin exposure, rapid vaginal delivery or predisposition to accelerated osteoporosis. Lumbar radiculopathy can be a feature of sacral stress fracture and it is more common (17.6%) than reported in the literature (2%). MRI is the preferred imaging modality for its safety profile in pregnancy and high sensitivity. A total of 70% reported normal bone mineral density (BMD). The mainstay treatment for sacral stress fractures includes relative bed rest, analgesia and modified weight-bearing exercises. Most patients have favourable outcome with complete symptom resolution.

CONCLUSION

Sacral stress fractures in the absence of osteoporosis are rare complications of pregnancy that can present with lumbar radiculopathy. Conservative management often produces good clinical outcomes.

Analysis of Parametric and Subharmonic Excitation in Push-Pull Driven Disk Resonator Gyroscopes

For micro-electromechanical system (MEMS) resonators, once the devices are fabricated and packaged, their intrinsic quality factors (Q) will be fixed and cannot be changed, which seriously limits the further improvement of the resonator’s performance. In this paper, parametric excitation is applied in a push-pull driven disk resonator gyroscope (DRG) to improve its sensitivity by an electrical pump, causing an arbitrary increase of the “effective Q”. However, due to the differential characteristics of the push-pull driving method, the traditional parametric excitation method is not applicable. As a result, two novel methods are proposed and experimentally carried out to achieve parametric excitation in the push-pull driven DRGs, resulting in a maximum “effective Q” of 2.24 × 10⁶ in the experiment, about a 7.6 times improvement over the intrinsic Q. Besides, subharmonic excitation is also theoretically analyzed and experimentally characterized. The stability boundary of parametric excitation, defined by a threshold voltage, is theoretically predicted and verified by related experiments. It is demonstrated that, when keeping the gyroscope’s vibration at a constant amplitude, the fundamental frequency driving voltage will decrease with the increasing of the parametric voltage and will drop to zero at its threshold value. In this case, the gyroscope operates in a generalized parametric resonance condition, which is called subharmonic excitation. The novel parametric and subharmonic excitation theories displayed in this paper are proven to be efficient and tunable dynamical methods with great potential for adjusting the quality factor flexibly, which can be used to further enhance the resonator’s performance.

Adipokinetic hormone enhances CarE-mediated chlorpyrifos resistance in the brown planthopper, Nilaparvata lugens

Adipokinetic hormone (AKH), the principal stress-responsive neurohormone in insects, has been implicated in insect responses to insecticides. However, the functionality of AKH and its mode of signalling in insecticide resistance are unknown. Herein, we demonstrated that the enhanced activity of carboxylesterases (CarEs) is involved in the chlorpyrifos resistance in Nilaparvata lugens [brown planthopper (BPH)]. Chlorpyrifos exposure significantly induced the expression of AKH and its receptor AKHR in the susceptible BPH (Sus), and these two AKH signalling genes were over-expressed in the chlorpyrifos-resistant strain (Res) compared to Sus. RNA interference (RNAi) against AKH or AKHR decreased the CarE activity and suppressed the BPH's resistance to chlorpyrifos in Res. Conversely, AKH peptide injection elevated the CarE activity and enhanced the BPH's survival against chlorpyrifos in Sus. Furthermore, five CarE genes were identified to be positively affected by the AKH pathway using RNAi and AKH injection. Among these CarE genes, CarE and Esterase E4-1 were found to be over-expressed in Res compared to Sus, and knockdown of either gene decreased the BPH's resistance to chlorpyrifos. In conclusion, AKH plays a role in enhancing chlorpyrifos resistance in the BPH through positive influence on the expression of CarE genes and CarE enzyme activity.

Constrained minimal-interface structures in polycrystalline copper with extremely fine grains

Metals usually exist in the form of polycrystalline solids, which are thermodynamically unstable because of the presence of disordered grain boundaries. Grain boundaries tend to be eliminated through coarsening when heated or by transforming into metastable amorphous states when the grains are small enough. Through experiments and molecular dynamics simulations, we discovered a different type of metastable state for extremely fine-grained polycrystalline pure copper. After we reduced grain sizes to a few nanometers with straining, the grain boundaries in the polycrystals evolved into three-dimensional minimal-interface structures constrained by twin boundary networks. This polycrystalline structure that underlies what we call a Schwarz crystal is stable against grain coarsening, even when close to the equilibrium melting point. The polycrystalline samples also exhibit a strength in the vicinity of the theoretical value.

Full-length-transcriptomic analysis in mice and human heart using Single-Molecule Real-time Sequencing (SMRT) identified 15 novel isoforms and a novel promoter region of PGC1-alpha

Background

Alternative splicing is a process by which exons within a pre-mRNA are joined or skipped, resulting in isoforms being encoded by a single gene. Alternative Splicing affecting transcription factors may have substantial impact on cellular dynamics. The PPARG Coactivator 1 Alpha (PGC1-α), is a major modulator in energy metabolism. Data from murine skeletal muscle revealed distinctive isoform patterns giving rise to different phenotypes, i.e. mitogenesis and hypertrophy. Here, we aimed to establish a complete dataset of isoforms in murine and human heart applying single-molecule real-time (SMRT)-sequencing as novel approach to identify transcripts without need for assembly, resulting in true full-length sequences. Moreover, we aimed to unravel functional relevance of the various isoforms during experimental ischemia reperfusion (I/R).

Methods

RNA-Isolation was performed in murine (C57Bl/6J) or human heart tissue (obtained during LVAD-surgery), followed by library preparation and SMRT-Sequencing. Bioinformatic analysis was done using a modified IsoSeq3-Pipeline and OS-tools. Identification of PGC1-α isoforms was fulfilled by similarity search against exonic sequences within the full-length, non-concatemere (FLNC) reads. Isoforms with Open-Reading-Frame (ORF) were manually curated and validated by PCR and Sanger-Sequencing. I/R was induced by ligature of the LAD for 45 min in mice on standard chow as well as on high-fat-high-sucrose diet. Area At Risk (AAR) and remote tissue were collected three and 16 days after I/R or sham-surgery (n=4 per time point). Promotor patterns were analyzed by qPCR.

Results

Deciphering the full-length transcriptome of murine and human heart resulted in ∼60000 Isoforms with 99% accuracy on mRNA-sequence. Focusing on murine PGC1-α-isoforms we discovered and verified 15 novel transcripts generated by hitherto unknown splicing events. Additionally, we identified a novel Exon 1 originating between the known promoters followed by a valid ORF, suggesting the discovery of a novel promoter. Remarkably, we found a homologous novel Exon1 in human heart, suggesting conservation of the postulated promoter.

In I/R the AAR exhibited a significant lower expression of established and novel promoters compared to remote under standard chow 3d post I/R. 16d post I/R, the difference between AAR & Remote equalized in standard chow while remaining under High-Fat-Diet.

Conclusion

Applying SMRT-technique, we generated the first time a complete full-length-transcriptome of the murine and human heart, identifying 15 novel potentially coding transcripts of PGC1-α and a novel exon 1. These transcripts are differentially regulated in experimental I/R in AAR and remote myocardium, suggesting transcriptional regulation and alternative splicing modulating PGC1-α function in heart. Differences between standard chow and high fat diet suggest impact of impaired glucose metabolism on regulatory processes after myocardial infarction.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Collaborative Research Centre 1116 (German Research Foundation)

Rapid heating induced ultrahigh stability of nanograined copper

Inherent thermal and mechanical instability of nanograined materials bottlenecks their processing and technological applications. In addition to the traditional stabilization strategy, which is based on alloying, grain boundary relaxation was recently found to be effective in stabilizing nanograined pure metals. Grain boundary relaxation can be induced by deforming very fine nanograins below a critical size, typically several tens of nanometers. Here, we found that rapid heating may trigger intensive boundary relaxation of pure Cu nanograins with sizes up to submicrometers, a length scale with notable instability in metals. The rapidly heated Cu nanograins remain stable at temperatures as high as 0.6 T _m (melting point), even higher than the recrystallization temperature of deformed coarse-grained Cu. The thermally induced grain boundary relaxation originating from the generation of high-density nanotwins offers an alternative approach to stabilizing nanostructured materials.

Twist1/2 activates MMP2 expression via binding to its promoter in colorectal cancer

OBJECTIVE

This study aimed to characterize the effect of Twist2 on epithelial-to-mesenchymal transition (EMT) and the invasive potential of colorectal cancer (CRC) cells and to explore the mechanisms underlying the regulative effect of Twist1 and Twist2 on matrix metalloproteinase 2 (MMP2) expression in CRC.

PATIENTS AND METHODS

Data mining was performed in colorectal cancer cohort (COADREAD) in the Cancer Genome Atlas (TCGA-COADREAD). CRC LoVo and HCT116 cells were used as in vitro cell models.

RESULTS

CRC tumors with lymphatic invasion (N = 102) had a significantly higher expression of TWIST1 (p = 0.01) and TWIST2 (p = 0.02) than the lymphatic invasion negative cases (N = 228). TWIST2 overexpression enhanced EMT and the invasive potential of the CRC LoVo and HCT116 cells, while TWIST2 knockdown reversed the EMT process and weakened the invasive potential of the cells. TWIST1 and TWIST2 were co-upregulated with MMP2 and MMP9 in COADREAD cohort. TWIST1 or TWIST2 overexpression significantly elevated nuclear β-catenin accumulation, which is a known signaling pathway elevating MMP2 and MMP9 expression. More importantly, we found that both Twist1 and Twist2 could transcriptionally activate MMP2 via directly binding to its promoter. However, this mechanism was not observed in the MMP9 promoter.

CONCLUSIONS

TWIST1/2 is associated with lymphatic invasion in CRC. TWIST2 upregulation enhances EMT and the invasive potential of CRC cells. TWIST1/2 can enhance the Wnt/β-catenin signaling pathway in CRC cells. In addition, Twist1/2 can bind to the MMP2 promoter and promote its transcription.