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Orthopaedics & Traumatology, Surgery &... Oct 2021Since its introduction in the early 1960s, the multiple cannulated screw fixation method has been developed for use in femoral neck fractures (FNFs); however, the... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Since its introduction in the early 1960s, the multiple cannulated screw fixation method has been developed for use in femoral neck fractures (FNFs); however, the parallelism of screws remains controversial.
MATERIALS AND METHODS
MEDLINE, Embase, and the Cochrane Library were systematically searched for studies published before June 2, 2020, that compared the use of parallel and non-parallel screw fixation for the treatment of FNF. The pooled analysis was designed to identify differences between the two groups and focused on postoperative complications, including fracture nonunion and osteonecrosis of the femoral head (ONFH).
RESULTS
Over four studies, we enrolled 445 patients, including 195 patients with fixed FNF with parallel trajectory screws and 250 patients with fixed FNF with non-parallel screws. The pooled analysis showed no difference in the nonunion rates (odds ratio (OR)=0.91; 95% confidence interval (CI), 0.24-3.44; p=0.89) and no significant difference in the incidence of ONFH between parallel and non-parallel screw fixation (OR=0.74; 95% CI: 0.21-2.63; p=0.64).
CONCLUSIONS
The results of this meta-analysis reveal that screw parallelism in multiple cannulated screw fixation of FNF has no relationship with either the fracture nonunion rate or the incidence of postoperative ONFH.
LEVEL OF EVIDENCE
III; meta-analysis.
Topics: Bone Screws; Femoral Neck Fractures; Fracture Fixation, Internal; Fractures, Ununited; Humans; Postoperative Complications
PubMed: 34217865
DOI: 10.1016/j.otsr.2021.103005 -
Trends in Ecology & Evolution Apr 2018The quest for understanding how species interactions modulate diversity has progressed by theoretical and empirical advances following niche and network theories. Yet,... (Review)
Review
The quest for understanding how species interactions modulate diversity has progressed by theoretical and empirical advances following niche and network theories. Yet, niche studies have been limited to describe coexistence within tropic levels despite incorporating information about multi-trophic interactions. Network approaches could address this limitation, but they have ignored the structure of species interactions within trophic levels. Here we call for the integration of niche and network theories to reach new frontiers of knowledge exploring how interactions within and across trophic levels promote species coexistence. This integration is possible due to the strong parallelisms in the historical development, ecological concepts, and associated mathematical tools of both theories. We provide a guideline to integrate this framework with observational and experimental studies.
Topics: Biodiversity; Ecosystem; Models, Biological
PubMed: 29471971
DOI: 10.1016/j.tree.2018.01.007 -
Journal of Evolutionary Biology Jun 2021Research on the genomics of adaptation is rapidly changing. In the last few decades, progress in this area has been driven by methodological advances, not only in the...
Research on the genomics of adaptation is rapidly changing. In the last few decades, progress in this area has been driven by methodological advances, not only in the way increasingly large amounts of molecular data are generated (e.g. with high-throughput sequencing), but also in the way these data are analysed. This includes a growing appreciation and quantitative treatment of covariation among units within the same data type (e.g. genes) or across data types (e.g. genes and phenotypes). The development and adoption of more and more integrative tools have resulted in richer and more interesting empirical work. This special issue - comprising methodological, empirical, and review papers - aims to capture a 'snapshot' of this rapidly evolving field. We discuss in particular three important themes in the study of adaptation: the genetic architecture of adaptive variation, protein-coding and regulatory changes, and parallel evolution. We highlight how more traditional key themes in the study of genetic architecture (e.g. the number of loci underlying adaptive traits and the distribution of their effects) are now being complemented by other factors (e.g. how patterns of linkage and number of loci interact to affect the ability to adapt). Similarly, apart from addressing the relative importance of protein-coding and regulatory changes, we now have the tools to look in-depth at specific types of regulatory variation to gain a clearer picture of regulatory networks. Finally, parallel evolution has always been central to the study of adaptation, but now we are often able to address the question of whether - and to what extent - parallelism at the organismal or phenotypic level is matched by parallelism at the genetic level. Perhaps most importantly, we can now determine what mechanisms are driving parallelism (or lack thereof) across levels of biological organization. All these recent methodological developments open up new directions for future studies of adaptive changes across traits, levels of biological organization, demographic contexts and time scales.
Topics: Adaptation, Biological; Biological Evolution; Genetic Variation; Genomics
PubMed: 34145685
DOI: 10.1111/jeb.13871 -
Developmental Biology Jan 2018Studying regeneration in animals where and when it occurs is inherently interesting and a challenging research topic within developmental biology. Historically,... (Review)
Review
Studying regeneration in animals where and when it occurs is inherently interesting and a challenging research topic within developmental biology. Historically, vertebrate regeneration has been investigated in animals that display enhanced regenerative abilities and we have learned much from studying organ regeneration in amphibians and fish. From an applied perspective, while regeneration biologists will undoubtedly continue to study poikilothermic animals (i.e., amphibians and fish), studies focused on homeotherms (i.e., mammals and birds) are also necessary to advance regeneration biology. Emerging mammalian models of epimorphic regeneration are poised to help link regenerative biology and regenerative medicine. The regenerating rodent digit tip, which parallels human fingertip regeneration, and the regeneration of large circular defects through the ear pinna in spiny mice and rabbits, provide tractable, experimental systems where complex tissue structures are regrown through blastema formation and morphogenesis. Using these models as examples, we detail similarities and differences between the mammalian blastema and its classical counterpart to arrive at a broad working definition of a vertebrate regeneration blastema. This comparison leads us to conclude that regenerative failure is not related to the availability of regeneration-competent progenitor cells, but is most likely a function of the cellular response to the microenvironment that forms following traumatic injury. Recent studies demonstrating that targeted modification of this microenvironment can restrict or enhance regenerative capabilities in mammals helps provide a roadmap for eventually pushing the limits of human regeneration.
Topics: Amputation, Surgical; Animals; Antlers; Deer; Ear Auricle; Finger Injuries; Fingers; Humans; Mammals; Mice; Morphogenesis; Murinae; Regeneration; Stem Cells; Toes; Wound Healing
PubMed: 29291973
DOI: 10.1016/j.ydbio.2017.08.007 -
Science Advances Jul 2022pH controls a large repertoire of chemical and biochemical processes in water. Densely arrayed pH microenvironments would parallelize these processes, enabling their...
pH controls a large repertoire of chemical and biochemical processes in water. Densely arrayed pH microenvironments would parallelize these processes, enabling their high-throughput studies and applications. However, pH localization, let alone its arrayed realization, remains challenging because of fast diffusion of protons in water. Here, we demonstrate arrayed localizations of picoliter-scale aqueous acids, using a 256-electrochemical cell array defined on and operated by a complementary metal oxide semiconductor (CMOS)-integrated circuit. Each cell, comprising a concentric pair of cathode and anode with their current injections controlled with a sub-nanoampere resolution by the CMOS electronics, creates a local pH environment, or a pH "voxel," via confined electrochemistry. The system also monitors the spatiotemporal pH profile across the array in real time for precision pH control. We highlight the utility of this CMOS pH localizer-imager for high-throughput tasks by parallelizing pH-gated molecular state encoding and pH-regulated enzymatic DNA elongation at any selected set of cells.
PubMed: 35895813
DOI: 10.1126/sciadv.abm6815 -
Frontiers in Plant Science 2022The concept of "cell type," though fundamental to cell biology, is controversial. Cells have historically been classified into types based on morphology, physiology, or... (Review)
Review
The concept of "cell type," though fundamental to cell biology, is controversial. Cells have historically been classified into types based on morphology, physiology, or location. More recently, single cell transcriptomic studies have revealed fine-scale differences among cells with similar gross phenotypes. Transcriptomic snapshots of cells at various stages of differentiation, and of cells under different physiological conditions, have shown that in many cases variation is more continuous than discrete, raising questions about the relationship between cell type and cell state. Some researchers have rejected the notion of fixed types altogether. Throughout the history of discussions on cell type, cell biologists have compared the problem of defining cell type with the interminable and often contentious debate over the definition of arguably the most important concept in systematics and evolutionary biology, "species." In the last decades, systematics, like cell biology, has been transformed by the increasing availability of molecular data, and the fine-grained resolution of genetic relationships have generated new ideas about how that variation should be classified. There are numerous parallels between the two fields that make exploration of the "cell types as species" metaphor timely. These parallels begin with philosophy, with discussion of both cell types and species as being either individuals, groups, or something in between (e.g., homeostatic property clusters). In each field there are various different types of lineages that form trees or networks that can (and in some cases do) provide criteria for grouping. Developing and refining models for evolutionary divergence of species and for cell type differentiation are parallel goals of the two fields. The goal of this essay is to highlight such parallels with the hope of inspiring biologists in both fields to look for new solutions to similar problems outside of their own field.
PubMed: 36072310
DOI: 10.3389/fpls.2022.868565 -
Frontiers in Plant Science 2022Nectaries are a promising frontier for plant evo-devo research, and are particularly fascinating given their diversity in form, position, and secretion methods across...
Nectaries are a promising frontier for plant evo-devo research, and are particularly fascinating given their diversity in form, position, and secretion methods across angiosperms. Emerging model systems permit investigations of the molecular basis for nectary development and nectar secretion across a range of taxa, which addresses fundamental questions about underlying parallelisms and convergence. Herein, we explore nectary development and nectar secretion in the emerging model taxa, (Cleomaceae), which exhibits a prominent adaxial nectary. First, we characterized nectary anatomy and quantified nectar secretion to establish a foundation for quantitative and functional gene experiments. Next, we leveraged RNA-seq to establish gene expression profiles of nectaries across three key stages of development: pre-anthesis, anthesis, and post-fertilization. We then performed functional studies on five genes that were putatively involved in nectary and nectar formation: (, (, and a highly expressed but uncharacterized transcript. These experiments revealed a high degree of functional convergence to homologues from other core Eudicots, especially . , redundantly with and , are required for nectary initiation. Concordantly, is essential for nectar formation and secretion, which indicates that the process is eccrine based in . While demonstration of conservation is informative to our understanding of nectary evolution, questions remain. For example, it is unknown which genes are downstream of the developmental initiators , , and , or what role the gene family plays in nectary initiation in this family. Further to this, we have initiated a characterization of associations between nectaries, yeast, and bacteria, but more research is required beyond establishing their presence. is an excellent model for continued research into nectary development because of its conspicuous nectaries, short generation time, and close taxonomic distance to .
PubMed: 36844906
DOI: 10.3389/fpls.2022.1085900 -
Frontiers in Neuroscience 2015Multi-modal magnetic resonance imaging (MRI) techniques are widely applied in human brain studies. To obtain specific brain measures of interest from MRI datasets, a... (Review)
Review
Multi-modal magnetic resonance imaging (MRI) techniques are widely applied in human brain studies. To obtain specific brain measures of interest from MRI datasets, a number of complex image post-processing steps are typically required. Parallel workflow tools have recently been developed, concatenating individual processing steps and enabling fully automated processing of raw MRI data to obtain the final results. These workflow tools are also designed to make optimal use of available computational resources and to support the parallel processing of different subjects or of independent processing steps for a single subject. Automated, parallel MRI post-processing tools can greatly facilitate relevant brain investigations and are being increasingly applied. In this review, we briefly summarize these parallel workflow tools and discuss relevant issues.
PubMed: 26029043
DOI: 10.3389/fnins.2015.00171 -
Chemical Science Aug 2023We present an automated droplet reactor platform possessing parallel reactor channels and a scheduling algorithm that orchestrates all of the parallel hardware...
We present an automated droplet reactor platform possessing parallel reactor channels and a scheduling algorithm that orchestrates all of the parallel hardware operations and ensures droplet integrity as well as overall efficiency. We design and incorporate all of the necessary hardware and software to enable the platform to be used to study both thermal and photochemical reactions. We incorporate a Bayesian optimization algorithm into the control software to enable reaction optimization over both categorical and continuous variables. We demonstrate the capabilities of both the preliminary single-channel and parallelized versions of the platform using a series of model thermal and photochemical reactions. We conduct a series of reaction optimization campaigns and demonstrate rapid acquisition of the data necessary to determine reaction kinetics. The platform is flexible in terms of use case: it can be used either to investigate reaction kinetics or to perform reaction optimization over a wide range of chemical domains.
PubMed: 37621435
DOI: 10.1039/d3sc02082g -
Central European Journal of Urology 2015Obesity in men is associated with infertility in numerous studies. The current trend for decline in semen parameters parallels the increasing prevalence of obesity... (Review)
Review
INTRODUCTION
Obesity in men is associated with infertility in numerous studies. The current trend for decline in semen parameters parallels the increasing prevalence of obesity worldwide. In addition to impaired semen quality, fertility among obese men may be affected by sexual dysfunction, endocrinopathy, aromatization activity, psychological and thermal effects, sleep apnea, leptin and minor toxins, and possibly the inflammatory and obstructive elements of epididymitis pathology. The variable degrees of certainty associated with these causes parallel the levels of supporting evidence. This search aims to shed lights on different conditions that obese men suffer from; as that makes the treatment of infertility more categorized.
MATERIAL AND METHODS
A PubMed search was conducted to identify clinical and pathological mechanisms linking obesity to male infertility.
RESULTS
Among the myriad of publications reviewed in this paper, impaired spermatogenesis and sexual dysfunction have been shown to drive other variables towards poor fertility potentials. The paper presented a new, detailed flow chart showing more factors and further interactions among conditions leading to infertility.
CONCLUSIONS
The prime hormonal defect in obese men is hypotestosteronaemia, which results in impaired spermatogenesis leading to poor fecundability. Studies have shown that most mechanisms accounting for reduced fertility potentials in overweight men are reversible.
PubMed: 25914843
DOI: 10.5173/ceju.2015.01.435