Tipping point

Overgeneralization and a lack of baseline data for microorganisms in high-latitude environments have restricted the understanding of the microbial response to climate change, which is needed to establish Antarctic conservation frameworks. To bridge this gap, we examined over 17,000 sequence variants of bacteria and microeukarya across the hyperarid Vestfold Hills and Windmill Islands regions of eastern Antarctica. Using an extended gradient forest model, we quantified multispecies response to variations along 79 edaphic gradients to explore the effects of change and wind-driven dispersal on community dynamics under projected warming trends...

Aim: To present a complex case of Ahmed tube exposure 6 months after the implantation associated with corneal melting and iris prolapse, and the surgical reposition that required multiple allografts and limbal reconstruction. Methods: A 60-year-old patient arrived at the emergency room with tube exposure combined with corneal melting and iris prolapse from a previously placed Ahmed valve 6 months prior. Our approach was to use one corneoscleral graft to repair the melted cornea and avoid further iris prolapse and a second scleral graft to cover the repositioned tube...

PURPOSE: Neuronavigation systems coupled with previously reported external anatomical landmarks assist neurosurgeons during intracranial procedures. We aimed to verify whether the posterior auricularis muscle (PAM) could be used as an external landmark for identifying the sigmoid sinus (SS) and the transverse-sigmoid sinus junction (TSSJ) during posterior cranial fossa surgery. METHODS: The PAM was dissected in 10 adult cadaveric heads, and after drilling the underlying bone, the relationships with the underlying SS and TSSJ were noted...

BACKGROUND: Most 3D-printed guiding templates require dissection of soft tissues to match the corresponding surfaces of the guiding templates. This study sought to explore the accuracy and acceptability of the novel 3D printed individualized guiding templates based on cutaneous fiducial markers in minimally invasive screw placement for pelvic fractures. METHODS: The printed template was tested on five high-fidelity biomimetic phantom models of the bony pelvis and its surrounding soft tissues as well as on two fresh frozen cadavers...

The sustainability of social-ecological systems within river deltas globally is in question as rapid development and environmental change trigger "negative" or "positive" tipping points depending on actors' perspectives, e.g. regime shift from abundant sediment deposition to sediment shortage, agricultural sustainability to agricultural collapse or shift from rural to urban land use. Using a systematic review of the literature, we show how cascading effects across anthropogenic, ecological, and geophysical processes have triggered numerous tipping points in the governance, hydrological, and land-use management of the world's river deltas...

Lightweight structures with a high stiffness-to-weight ratio always play a significant role in weight reduction in the aerospace sector. The exploration of non-conventional structures for aerospace applications has been a point of interest over the past few decades. The adaptation of lattice structure and additive manufacturing in the design can lead to improvement in mechanical properties and significant weight reduction. The practicality of the non-conventional wing structure with lattices infilled as a replacement for the conventional spar-ribs wing is determined through finite element analysis...

OBJECTIVE: To comparatively analyze the therapeutic effect of maxillary expansion combined with twin-block appliances (TBA) versus adenotonsillectomy (ATE) in the treatment of children with upper airway stenosis (UAS) complicated by malocclusion (MA), and to analyze the related factors affecting the changes of the upper airway sagittal diameter. METHODS: From October 2020 to October 2022, 54 children with UAS complicated by class II MA were treated at Zhenjiang Stomatological Hospital and Liyang People's Hospital...

OBJECTIVE: This study aims to describe a precise description of suture lateralization (SL) technique and evaluate its effectiveness and safety in management of bilateral vocal fold paralysis (BVFP). METHOD: A preclinical cadaveric study followed by application on a case series of BVFP patients. After the preliminary study executed to precisely localize the optimal sites for needle insertion, a prospective interventional study was conducted on 19 subjects presenting with respiratory distress due to BVFP...

Rhizosphere pH determines nutrient bioavailability, but this pH is difficult to measure. Standard pH tests require adding water to growth media. This dilutes hydrogen ion activity and increases pH. We used a novel, in situ , pointed-tip electrode to estimate rhizosphere pH without dilution. Measurements from this electrode matched a research-grade pH meter in hydroponic nutrient solutions. We then compared measurements from this electrode to saturated paste and pour-through methods in peat moss, coconut coir, and pine bark...

This perspective encompasses a focused review of the literature leading to a tipping point in electroanalytical chemistry. We tie together the threads of a "revolution" quietly in the making for years through the work of many authors. Long-held misconceptions about the use of background subtraction in fast voltammetry are addressed. We lay out future advantages that accompany background-inclusive voltammetry, particularly when paired with modern machine-learning algorithms for data analysis.

BACKGROUND: Prominent lower front teeth (Class III malocclusion) may be due to jaw or tooth position or both. The upper jaw (maxilla) can be too far back or the lower jaw (mandible) too far forward; the upper front teeth (incisors) may be tipped back or the lower front teeth tipped forwards. Orthodontic treatment uses different types of braces (appliances) fitted inside or outside the mouth (or both) and fixed to the teeth. A facemask is the most commonly reported non-surgical intervention used to correct Class III malocclusion...

Serial sectioning and 3D image reconstruction methods were applied to elucidate the structures of the apices of root vascular cylinders (VCs) in taxa of the Poaceae: Zea mays "Honey Bantam", Z. mays ssp. mexicana , Hordeum vulgare and Oryza sativa . The primary and nodal roots were investigated. Observations were performed using high-quality sectioning and 3D image-processing techniques improved and developed by the authors. We found that a quiescent uniseriate plerome was located at the most distal part of each VC...

The shear stress transport turbulence model is employed to conduct a detailed study of flow characteristics at the highest efficiency point and near-stall point in a full-channel 1.5-stage compressor in this paper. The simulation results for the compressor's total pressure ratio and efficiency exhibit good agreement with experimental data. Emphasis is placed on examining the internal flow structure in the tip area of the compressor rotor under near-stall conditions. The results reveal that significant differences in flow structure primarily occur in the tip area as the compressor approaches stall...

Some individuals are able to maintain their cognitive abilities despite the presence of significant Alzheimer's Disease (AD) neuropathological changes. This discrepancy between cognition and pathology has been labeled as resilience and has evolved into a widely debated concept. External factors such as cognitive stimulation are associated with resilience to AD, but the exact cellular and molecular underpinnings are not completely understood. In this review, we discuss the current definitions used in the field, highlight the translational approaches used to investigate resilience to AD and summarize the underlying cellular and molecular substrates of resilience that have been derived from human and animal studies, which have received more and more attention in the last few years...

High-speed atomic force microscopy (HS-AFM) is a popular molecular imaging technique for visualizing single-molecule biological processes in real-time due to its ability to image under physiological conditions in liquid environments. The photothermal off-resonance tapping (PORT) mode uses a drive laser to oscillate the cantilever in a controlled manner. This direct cantilever actuation is effective in the MHz range. Combined with operating the feedback loop on the time domain force curve rather than the resonant amplitude, PORT enables high-speed imaging at up to ten frames per second with direct control over tip-sample forces...

PURPOSE: To compare the forming ability of four kinds of nickel-titanium instrument preparation resin for simulated curved root canal. METHODS: A total of 40 single bend resin simulated root canals were randomly divided into 4 groups with 10 in each group. Four kinds of nickel-titanium instruments (ProTaper, HyFlex EDM, WaveOne Gold and Reciproc Blue) were used for root canal preparation, and divided into group A, group B, group C and group D. The preparation time of the four groups was compared, the root canal images before and after preparation were analyzed by computer image analysis software, and the changes of the preparation time, curvature and curvature radius of the four groups were recorded...

Exogenous exposures to the triose sugar dihydroxyacetone (DHA) occur from sunless tanning products and electronic cigarette aerosol. Once inhaled or absorbed, DHA enters cells, is converted to dihydroxyacetone phosphate (DHAP), and incorporated into several metabolic pathways. Cytotoxic effects of DHA vary across the cell types depending on the metabolic needs of the cells, and differences in the generation of reactive oxygen species (ROS), cell cycle arrest, and mitochondrial dysfunction have been reported...

11-Nor-9-carboxy-Δ9-tetrahydrocannabinol (Δ9-THCCOOH) is the most frequently detected illicit drug metabolite in the military drug testing program. An increasing number of specimens containing unresolved Δ8-THCCOOH prompted the addition of this analyte to the Department of Defense (DoD) drug testing panel. A method was developed and validated for the quantitative confirmation of the carboxylated metabolites of Δ8- and Δ9-THC in urine samples utilizing automated pipette tip dispersive solid phase extraction and analysis by liquid chromatography tandem mass spectrometry (LC-MS/MS)...

Major amputations of the lower extremity may be required after trauma and a variety of underlying diseases such as peripheral vascular disease, diabetes, and malignancies. The goal of any major amputation is an optimal functional result with a maximum limb length in combination with optimal wound healing. The preservation of the knee joint is essential for successful rehabilitation, and this is best achieved by the Burgess below-knee amputation (BKA). Whenever a BKA is not possible, the Gritti-Stokes amputation is our first choice...

OBJECTIVE: In neural electrical stimulation, safe stimulation guidelines are essential to deliver efficient treatment by avoiding neural damage and electrode degradation. The widely used Shannon's limit, k, gives conditions on the stimulation parameters to avoid neural damage, however, underlying damage mechanisms are not fully understood. Moreover, the translation from bench testing to in vivo experiments still presents some challenges, including the increased polarisation observed, which may influence charge-injection mechanisms...