Biomechanical effects of the implant material and implant–abutment interface in immediately loaded small-diameter implants

Objective

Small-diameter implants have been available since the 1990s, but few studies have analyzed their mechanical properties. This study evaluated the effects of the implant material and the implant–abutment connection designs on the primary stability and the marginal bone strain of small-diameter implant subject to immediate loading.

Materials and methods

Insertion torque value (ITV), implant stability quotient (ISQ), and Periotest value (PTV) of three implant systems with four parameters (titanium, titanium alloy, internal and external hexagon connections) were measured after placing implants into artificial type 2 jaw-bone models. Specimens were tested under both vertical and oblique static loads at 190 N. Peak values of the principal bone strain were recorded and analyzed statistically by the Kruskal–Wallis test and multiple-comparisons Bonferroni test.

Results

PTV and ISQ were higher for the NIOSM311 (internal-hex and Ti alloy) and FOSM311 (external-hex and pure Ti) implants, respectively, than for the NOSM311 (external-hex and Ti alloy) implant. Under vertical loading the peak value of peri-implant bone strains did not differ significantly among these three implant systems. However, the peak bone strains were at least 32 % lower for the NIOSM311 and FOSM311 implants than for the NOSM311 implant under lateral loading.

Conclusions

The implant material and the implant–abutment connection design significantly influence the peri-implant bone strain of immediately loaded small-diameter implants, but barely affect their primary stability.

Clinical Relevance

A commercially pure titanium implant with an internal connection has the potential to reduce the risk of implant failure of small-diameter implant related to biomechanical complications.     

Practical aspects of electrophoretic deposition to produce commercially viable supercapacitor energy storage electrodes

Electrophoretic deposition (EPD) is a highly convenient and demonstrated industrial operation for the manufacture of surface coatings. Recent years are seeing increasing evidence in using this technique to produce energy storage electrodes (notably for lithium-ion batteries, solid-state devices, supercapacitors, and flow batteries), but their advancement for industrialisation remains unclear. Using activated carbon (AC) as an exemplary supercapacitor material, this study reports the practical aspects of porous energy storage electrodes produced by the EPD technique. Practical electrodes with commercially viable parameters are shown, specifically high density active material (in excess of 9.8 mg cm⁻²) and very thick coating layer (about 168 μm). Research investigations including colloidal electrolyte formulations, electrode deposition parameters and cell performance testing are reported. Materials and electrode properties were studied by various charactersisation tools. Prototype A7 sized pouch cells were assembled and tested to show evidence of practical EPD electrodes in a commercial cell format. Electrochemical performance of EPD over slurry casting is presented. In short, this research shows the successful production of practical EPD electrodes for electrochemical energy storage, which is directly relevant for scale-up industrial adoption and can be applied as a platform electrode manufacturing technology for any battery and supercapacitor materials.

Electrophoretic deposition (EPD) is a highly convenient and demonstrated industrial operation for coatings manufacture. It is now suitable for the production of practical energy storage electrodes for batteries, capacitors & solid-state devices.     

Ciliary melanin-concentrating hormone receptor 1 (MCHR1) is widely distributed in the murine CNS in a sex-independent manner

Melanin-concentrating hormone (MCH) is a ubiquitous vertebrate neuropeptide predominantly synthesized by neurons of the diencephalon that can act through two G protein-coupled receptors, called MCHR1 and MCHR2. The expression of Mchr1 has been investigated in both rats and mice, but its synthesis remains poorly described. After identifying an antibody that detects MCHR1 with high specificity, we employed immunohistochemistry to map the distribution of MCHR1 in the CNS of rats and mice. Multiple neurochemical markers were also employed to characterize some of the neuronal populations that synthesize MCHR1. Our results show that MCHR1 is abundantly found in a subcellular structure called the primary cilium, which has been associated, among other functions, with the detection of free neurochemical messengers present in the extracellular space. Ciliary MCHR1 was found in a wide range of areas, including the olfactory bulb, cortical mantle, striatum, hippocampal formation, amygdala, midline thalamic nuclei, periventricular hypothalamic nuclei, midbrain areas, and in the spinal cord. No differences were observed between male and female mice, and interspecies differences were found in the caudate-putamen nucleus and the subgranular zone. Ciliary MCHR1 was found in close association with several neurochemical markers, including tyrosine hydroxylase, calretinin, kisspeptin, estrogen receptor, oxytocin, vasopressin, and corticotropin-releasing factor. Given the role of neuronal primary cilia in sensing free neurochemical messengers in the extracellular fluid, the widespread distribution of ciliary MCHR1, and the diverse neurochemical populations who synthesize MCHR1, our data indicate that nonsynaptic communication plays a prominent role in the normal function of the MCH system.     

A sleep schedule incorporating naps benefits the transformation of hierarchical knowledge

Study ObjectivesThe learning brain establishes schemas (knowledge structures) that benefit subsequent learning. We investigated how sleep and having a schema might benefit initial learning followed by rearranged and expanded memoranda. We concurrently examined the contributions of sleep spindles and slow-wave sleep to learning outcomes.MethodsFifty-three adolescents were randomly assigned to an 8 h Nap schedule (6.5 h nocturnal sleep with a 90-minute daytime nap) or an 8 h No-Nap, nocturnal-only sleep schedule. The study spanned 14 nights, simulating successive school weeks. We utilized a transitive inference task involving hierarchically ordered faces. Initial learning to set up the schema was followed by rearrangement of the hierarchy (accommodation) and hierarchy expansion (assimilation). The expanded sequence was restudied. Recall of hierarchical knowledge was tested after initial learning and at multiple points for all subsequent phases. As a control, both groups underwent a No-schema condition where the hierarchy was introduced and modified without opportunity to set up a schema. Electroencephalography accompanied the multiple sleep opportunities.ResultsThere were main effects of Nap schedule and Schema condition evidenced by superior recall of initial learning, reordered and expanded memoranda. Improved recall was consistently associated with higher fast spindle density but not slow-wave measures. This was true for both nocturnal sleep and daytime naps.ConclusionA sleep schedule incorporating regular nap opportunities compared to one that only had nocturnal sleep benefited building of robust and flexible schemas, facilitating recall of the subsequently rearranged and expanded structured knowledge. These benefits appear to be strongly associated with fast spindles.Clinical Trial registration{"type":"clinical-trial","attrs":{"text":"NCT04044885","term_id":"NCT04044885"}}NCT04044885 (https://clinicaltrials.gov/ct2/show/{"type":"clinical-trial","attrs":{"text":"NCT04044885","term_id":"NCT04044885"}}NCT04044885).     

Epidemiology of tuberculosis and HIV coinfections in Singapore, 2000–2014

Cross‐matching of records between Singapore's tuberculosis and HIV registries showed that 3.3% of individuals with tuberculosis (TB) were coinfected with HIV (2000?2014), the TB incidence among individuals with HIV infection was 1.65 per 100 person‐years, and 53% of coinfections were diagnosed within 1 month of each other. The findings supported joint prevention programmes for early diagnosis and treatment.