The age-varying effects of adolescent stress on impulsivity and sensation seeking.

Adolescence is defined in part by heightened exposure and sensitivity to stressors. In a longitudinal cohort of youth at risk for substance use problems, we examined the age-varying relationship between stress exposure and traits that are central to the dual systems model. The positive associations between stress exposure, impulsivity, sensation seeking varied as function of age. Specifically, the influence of stress exposure on impulsivity strengthened during early adolescence and remained stable into early adulthood, while the influence of stress exposure on sensation seeking strengthened from early- to mid-adolescence and weakened thereafter. These findings suggest that the maturational imbalance between the capacity to regulate impulsive tendencies and sensation seeking may be exaggerated for youth who are exposed to a high number of stressors.

Machine Learning Models for Predicting Cytotoxicity of Nanomaterials.

The wide application of nanomaterials in consumer and medical products has raised concerns about their potential adverse effects on human health. Thus, more and more biological assessments regarding the toxicity of nanomaterials have been performed. However, the different ways the evaluations were performed, such as the utilized assays, cell lines, and the differences of the produced nanoparticles, make it difficult for scientists to analyze and effectively compare toxicities of nanomaterials. Fortunately, machine learning has emerged as a powerful tool for the prediction of nanotoxicity based on the available data. Among different types of toxicity assessments, nanomaterial cytotoxicity was the focus here because of the high sensitivity of cytotoxicity assessment to different treatments without the need for complicated and time-consuming procedures. In this review, we summarized recent studies that focused on the development of machine learning models for prediction of cytotoxicity of nanomaterials. The goal was to provide insight into predicting potential nanomaterial toxicity and promoting the development of safe nanomaterials.

Stress response asymmetries in African American emerging adults exposed to chronic social adversity.

Chronic stress is linked to social adversity and underlies many health disparities among ethnic minorities. Cortisol and salivary alpha-amylase (sAA) reflect sensitivity to adversity and are related to health outcomes. Our aim was to understand how social adversity influences biological responses to experimental and daily stressors in a sample of low-income African American emerging adults. In the three-week study, participants completed questionnaires, the Trier Social Stress Task (TSST), and provided four salivary samples. In week 2, participants collected saliva at home immediately after waking and just before bed for three days. Results demonstrated an asymmetrical pattern between cortisol and sAA reactivity that was related to experiences with racism and interpersonal trauma. Further, daily stress was related to lower morning and higher nighttime cortisol, indicating atypical diurnal rhythm. These findings are consistent with other forms of social adversity that lead to long-term changes in the HPA axis response pattern.LAY SUMMARYAfrican American emerging adults showed divergent cortisol and sAA responses.Social adversity predicted an asymmetrical response pattern for sAA and cortisol.Atypical diurnal rhythms were found for participants reporting high daily stress.

Mathematical modeling and digital design of an intensified filtration-washing-drying unit for pharmaceutical continuous manufacturing.

This paper introduces a comprehensive mathematical model of a novel integrated filter-dryer carousel system, designed for continuously filtering, washing and drying a slurry stream into a crystals cake. The digital twin includes models for dead-end filtration, cake washing and convective cake drying, based on dynamic multi-component mass, energy and momentum balances. For set of feed conditions and control inputs, the model allows tracking the solvents and impurities content in the cake (critical quality attributes, CQAs) throughout the whole process. The model parameters were identified for the isolation of paracetamol from a multi-component slurry, containing a non-volatile impurity. The calibrated model was used for identifying the probabilistic design space and maximum throughput for the process, expressing the combinations of the carousel feed conditions and control inputs for which the probability of meeting the target CQAs is acceptable.

Impact of fetal alcohol exposure on body systems: A systematic review.

UNLABELLED: Review of published manuscripts on fetal alcohol exposure on several body systems. METHOD: Articles in this review were found online using databases such as Medline, Medline Complete, PubMed, and Health Source: Nursing/Academic Edition. The following terms were searched: fetal alcohol spectrum disorders, fetal alcohol syndrome, prenatal alcohol exposure, and alcohol related birth defects. RESULTS: Thirteen articles were gathered, five original investigations and eight reviews. This review identified several abnormalities in the body systems discussed and their associations to fetal alcohol syndrome. CONCLUSIONS: Evidence shows that the brain was the most severely impacted organ of the body systems discussed. However, prenatal alcohol exposure causes several abnormalities within the heart, kidney, liver, gastrointestinal tract, and the endocrine systems. In addition, preventative measures need to be taken by mothers during pregnancy. Birth Defects Research (Part C), 2016. © 2016 Wiley Periodicals, Inc. Birth Defects Research (Part C) 108:174-180, 2016. © 2016 Wiley Periodicals, Inc.

Product Quality Research for Developing and Assessing Regulatory Submissions for Generic Cyclosporine Ophthalmic Emulsions.

Approval of the first generic 0.05% cyclosporine ophthalmic emulsion (COE) in the U.S. represents a milestone achievement of the science and research program in the U.S. Food and Drug Administration's Center for Drug Evaluation and Research (CDER). COE is a locally acting complex drug product indicated to increase tear production in patients whose production is presumed to be suppressed due to ocular inflammation associated with keratoconjunctivitis sicca. The path to approval required overcoming numerous scientific challenges to determining therapeutic equivalence to the reference listed drug. Researchers in CDER's Office of Pharmaceutical Quality and Office of Generic Drugs developed a quality by design approach to understand the effects of process and formulation variables on the product's critical quality attributes, including globule size distribution (GSD), turbidity, viscosity, zeta potential, surface tension, and osmolality. CDER researchers explored multiple techniques to perform physicochemical characterization and analyze the GSD including laser diffraction, nanoparticle tracking analysis, cryogenic transmission electron microscopy, dynamic light scattering, asymmetric field flow fractionation, and two-dimensional diffusion ordered spectroscopy nuclear magnetic resonance. Biphasic models to study drug transfer kinetics demonstrated that COEs with qualitative and quantitative sameness and comparable GSDs, analyzed using earth mover's distance, can be therapeutic equivalents. This body of research facilitated the review and approval of the first U.S. generic COE. In addition, the methods and fundamental understanding developed from this research may support the development and assessment of other complex generics. The approval of a generic COE should improve the availability of this complex drug product to U.S. patients.

The Family Biorhythm: Contributions of the HPA and HPG Axes to Neuroendocrine Attunement.

Objective: The vast majority of research on biobehavioral influences on development has focused on mothers and infants, whereas research on paternal biobehavioral influences remains sparse. This study aims to increase understanding of paternal influences on the biobehavioral dynamics of the family unit, using a multi-system approach. Methods: Participants consisted of 32 predominantly high-risk families recruited during pregnancy who completed monthly questionnaires and in-home visits when infants were 4, 12, and 18 months of age. In-home visits included semi-structured interaction tasks and saliva samples for cortisol and progesterone assays. Results: Mothers and infants, but not fathers and infants, showed adrenocortical attunement, with the strongest attunement at 18 months. Second, mothers' couple satisfaction did not significantly impact infants' cortisol levels or mother-infant cortisol attunement, but mothers' progesterone moderated the relationship between couple satisfaction and infant cortisol levels such that mothers with low couple satisfaction, but high progesterone, had infants with lower cortisol levels. Finally, mothers' and fathers' progesterone levels were attuned across the time points. Conclusions: This is some of the first evidence of the establishment of the family biorhythm and suggests that fathers play an indirect role in facilitating mother-infant adrenocortical attunement. Supplementary Information: The online version contains supplementary material available at 10.1007/s40750-023-00215-0.

Reduced alcohol use increases drink-refusal self-efficacy: Evidence from a contingency management study for DWI arrestees.

BACKGROUND: Several therapies and interventions to reduce drinking first target drink-refusal self-efficacy (DRSE) to influence drinking behavior. While higher self-efficacy scores are correlated with better outcomes, it is unclear that increased self-efficacy is the causative step leading to improved outcomes. Instead, this correlation may result from reduced drinking that increased self-efficacy. The current study sought to understand how changes in drinking behavior can influence DRSE. METHODS: Data were from 211 driving while intoxicated (DWI) arrestees participating in an 8-week contingency management (CM) study to reduce drinking. Some of participants were mandated by the courts to wear transdermal alcohol monitoring devices (Mandated group) and some were not mandated (Non Mandated group). All wore a transdermal alcohol monitor during the 8-week study and were randomized to CM or a Control condition stratified by the mandate group. Participants completed weekly assessments of DRSE. Group-based trajectory-modeling identified three drinking behavior trajectory groups. RESULTS: While there were no differences in baseline DRSE between the three trajectory groups, participants in the low- and moderate-frequency drinking behavior groups significantly increased DRSE across the study. CONCLUSION: The present study indicates that being able to maintain abstinence or reduce heavy drinking may increase DRSE.

Using PharmaPy with Jupyter Notebook to teach digital design in pharmaceutical manufacturing.

The use of digital tools in pharmaceutical manufacturing has gained traction over the past two decades. Whether supporting regulatory filings or attempting to modernize manufacturing processes to adopt new and quickly evolving Industry 4.0 standards, engineers entering the workforce must exhibit proficiency in modeling, simulation, optimization, data processing, and other digital analysis techniques. In this work, a course that addresses digital tools in pharmaceutical manufacturing for chemical engineers was adjusted to utilize a new tool, PharmaPy, instead of traditional chemical engineering simulation tools. Jupyter Notebook was utilized as an instructional and interactive environment to teach students to use PharmaPy, a new, open-source pharmaceutical manufacturing process simulator. Students were then surveyed to see if PharmaPy was able to meet the learning objectives of the course. During the semester, PharmaPy's model library was used to simulate both individual unit operations as well as multiunit pharmaceutical processes. Through the initial survey results, students indicated that: (i) through Jupyter Notebook, learning Python and PharmaPy was approachable from varied coding experience backgrounds and (ii) PharmaPy strengthened their understanding of pharmaceutical manufacturing through active pharmaceutical ingredient process design and development.

Effectiveness of contingency management using transdermal alcohol monitoring to reduce heavy drinking among driving while intoxicated (DWI) arrestees: A randomized controlled trial.

BACKGROUND: Driving while intoxicated (DWI) is a serious public health problem. However, treatment for DWI arrestees is not readily available. This study examines the effectiveness of a contingency management (CM) procedure using transdermal alcohol concentration (TAC) monitoring to reduce drinking among DWI arrestees. METHOD: The study participants were 216 DWI arrestees under pretrial and included both Mandated participants undergoing court-ordered TAC monitoring and Non-Mandated participants wearing a study-provided TAC monitor. Participants were randomly assigned to either a CM (Mandated = 35; Non-Mandated = 74) or a Control condition (Mandated = 37; Non-Mandated = 70) and completed the 8-week intervention. CM participants received $50/week for not exceeding a TAC of 0.02 g/dL during the previous week. Payments to Controls were yoked to the CM group. RESULTS: Among Non-Mandated participants, the probability of meeting the contingency was higher and remained stable (about 65%) over time in the CM group, whereas the probability was lower and declined in the Control group, widening the gaps in the probability between the study conditions (16.7%-24.1% greater in the CM group from visit 4 to 8, all p < 0.05). Among Mandated participants, the probability was not significantly different between conditions (p = 0.06-0.95). Furthermore, among Non-Mandated participants, the percentage of heavy drinking days remained low (9.16%-11.37%) in the CM group, whereas it was greater and increased over time (17.43%-26.59%) in the Control group. In Mandated participants, no significant differences in percent heavy drinking days were observed between conditions (p = 0.07-0.10). CONCLUSION: We found that contingency effects on alcohol use are more pronounced among frequent and heavy alcohol users, i.e., Non-Mandated DWI arrestees. However, for individuals whose drinking was already suppressed by existing contingencies (i.e., court-mandated TAC monitoring), our CM procedure did not produce additional reductions in drinking.

Dosage unit uniformity and dissolution testing of extended-release pharmaceutical products marketed in the U.S.

An international sampling study yielded 69 samples of extended-release prescription pharmaceuticals for legal sale in the U.S. Samples included 29 lots of innovator and 40 lots of generic solid oral extended-release drugs manufactured at 16 different facilities and containing 6 different active ingredients. Dosage unit uniformity and dissolution were tested for each lot. All samples met the relevant testing criteria for dosage unit uniformity and dissolution. There were no indications that manufacturer or region impacted a product's acceptability for use by patients. The variability of attributes was used to calculate a process performance index (Ppk) for each facility. Higher Ppk values suggest less variability relative to specification limits. Only two manufacturers fell below a 4-sigma manufacturing benchmark Ppk of 1.33 for dosage unit uniformity: a European manufacturer of a brand drug and an Asian manufacturer of a generic drug. Conversely, all but four manufacturers fell below a 4-sigma benchmark for the minimum Ppk across their product's dissolution timepoints: generic drug manufacturers in India (two), the U.S., and Canada. Compared to the immediate-release products of a previous study, Ppks were generally lower for extended-release products. A retrospective analysis found that manufacturers performing below median Ppks submitted more Field Alert Reports after the end of the sampling period.

Whey-Adapted versus Natural Cow's Milk Formulation: Distinctive Feeding Responses and Post-Ingestive c-Fos Expression in Laboratory Mice.

The natural 20:80 whey:casein ratio in cow's milk (CM) for adults and infants is adjusted to reflect the 60:40 ratio of human milk, but the feeding and metabolic consequences of this adjustment have been understudied. In adult human subjects, the 60:40 CM differently affects glucose metabolism and hormone release than the 20:80 CM. In laboratory animals, whey-adapted goat's milk is consumed in larger quantities. It is unknown whether whey enhancement of CM would have similar consequences on appetite and whether it would affect feeding-relevant brain regulatory mechanisms. In this set of studies utilizing laboratory mice, we found that the 60:40 CM was consumed more avidly than the 20:80 control formulation by animals motivated to eat by energy deprivation and by palatability (in the absence of hunger) and that this hyperphagia stemmed from prolongation of the meal. Furthermore, in two-bottle choice paradigms, whey-adapted CM was preferred against the natural 20:80 milk. The intake of the whey-adapted CM induced neuronal activation (assessed through analysis of c-Fos expression in neurons) in brain sites promoting satiation, but importantly, this activation was less pronounced than after ingestion of the natural 20:80 whey:casein CM. Activation of hypothalamic neurons synthesizing anorexigenic neuropeptide oxytocin (OT) was also less robust after the 60:40 CM intake than after the 20:80 CM. Pharmacological blockade of the OT receptor in mice led to an increase in the consumption only of the 20:80 CM, thus, of the milk that induced greater activation of OT neurons. We conclude that the whey-adapted CM is overconsumed compared to the natural 20:80 CM and that this overconsumption is associated with weakened responsiveness of central networks involved in satiety signalling, including OT.

Application of PharmaPy in the digital design of the manufacturing process of an active pharmaceutical ingredient.

Flowsheet design and optimization constitute one of the key challenges in the chemical engineering and process optimization communities. Software tools for digital design and flowsheet simulation are readily available for traditional chemical processing problems such as distillation and hydrocarbon processing, however tools for pharmaceutical manufacturing are much less widely developed. This paper introduces, PharmaPy, a Python-based modelling platform for pharmaceutical facility design and optimization. The versatility of the platform is demonstrated in simulating both continuous and batch process flowsheets.

Adjustment of Whey:Casein Ratio from 20:80 to 60:40 in Milk Formulation Affects Food Intake and Brainstem and Hypothalamic Neuronal Activation and Gene Expression in Laboratory Mice.

Adjustment of protein content in milk formulations modifies protein and energy levels, ensures amino acid intake and affects satiety. The shift from the natural whey:casein ratio of ~20:80 in animal milk is oftentimes done to reflect the 60:40 ratio of human milk. Studies show that 20:80 versus 60:40 whey:casein milks differently affect glucose metabolism and hormone release; these data parallel animal model findings. It is unknown whether the adjustment from the 20:80 to 60:40 ratio affects appetite and brain processes related to food intake. In this set of studies, we focused on the impact of the 20:80 vs. 60:40 whey:casein content in milk on food intake and feeding-related brain processes in the adult organism. By utilising laboratory mice, we found that the 20:80 whey:casein milk formulation was consumed less avidly and was less preferred than the 60:40 formulation in short-term choice and no-choice feeding paradigms. The relative PCR analyses in the hypothalamus and brain stem revealed that the 20:80 whey:casein milk intake upregulated genes involved in early termination of feeding and in an interplay between reward and satiety, such as melanocortin 3 receptor (MC3R), oxytocin (OXT), proopiomelanocortin (POMC) and glucagon-like peptide-1 receptor (GLP1R). The 20:80 versus 60:40 whey:casein formulation intake differently affected brain neuronal activation (assessed through c-Fos, an immediate-early gene product) in the nucleus of the solitary tract, area postrema, ventromedial hypothalamic nucleus and supraoptic nucleus. We conclude that the shift from the 20:80 to 60:40 whey:casein ratio in milk affects short-term feeding and relevant brain processes.

Quebracho tannins aid in the control of Eimeria spp. and gastrointestinal nematodes in lambs and goat kids.

The objective was to examine the effects of supplementary quebracho on control of coccidiosis and gastrointestinal nematodes in lambs and kids. In Exp. 1, naturally infected lambs weaned (87.8 ± 0.4 days of age; day 0) in January (winter) were blocked by sex and randomly assigned (n = 10/treatment) to receive supplement with or without 100 g/lamb of quebracho for 28 days. In Exp. 2, single or twin rearing ewes were randomly assigned into two groups, and naturally infected lambs were fed control (n = 28) or quebracho (100 g/lamb of quebracho tannins in feed; n = 27) between -28 and 21 days (weaning = day 0; 70.8 ± 0.1 days of age). In Exp. 3, weaned doe kids (57.6 ± 2.0 days of age) were randomly assigned to receive alfalfa (Medicago sativa) supplement with (n = 9) or without (n = 8) 50 g/kid quebracho or sericea lespedeza (Lespedeza cuneata) with quebracho (n = 8) for 21 days. Fecal oocyst count (FOC), nematode egg counts (FEC), fecal score, dag score (soiling around rear quarters), and blood packed cell volume (PCV) were determined every 7 days. Data were analyzed as repeated measures using mixed models. In Exp. 1, FOC decreased in quebracho-fed lambs (diet × time, P < 0.001) but FEC was similar between treatments during the feeding period (P = 0.19). Packed cell volume (P = 0.19) and fecal score (P = 0.42) were similar between groups. Quebracho-fed lambs had a greater dag score initially (diet × time, P = 0.02), but were similar by day 42 (P = 0.72). In Exp. 2, FOC remained low (P = 0.02), PCV tended to decrease (P = 0.06), but FEC increased on days 14 and 21 (diet × time; P < 0.001) in quebracho compared with control-fed lambs. Quebracho-fed lambs had lower fecal score (diet × time; P = 0.005) but higher dag score (diet × time; P < 0.001). In Exp. 3, FOC of kids fed quebracho (alfalfa or sericea lespedeza supplement) was lower than control (P < 0.001). Fecal score of kids fed sericea lespedeza compared with alfalfa were lower regardless of quebracho (P = 0.01). There were no differences among treatments for dag, FEC, PCV, or body weight (P> 0.10). Quebracho was effective in reducing FOC but not clinical signs of coccidiosis in both lambs and kids, and may not be highly digestible in lambs as it caused loose stools.

Excessive Consumption of Sugar: an Insatiable Drive for Reward.

PURPOSE OF REVIEW: Eating behavior provides energy to ensure proper functioning of the organism. Reward aids in seeking foods that bring energy and pleasant taste, whose consumption is safe. As evidenced by the obesity "epidemic" which largely stems from overeating, reward becomes a detriment when palatable tastants are available in unlimited quantities. This review presents recent evidence on mechanisms underlying palatability-driven excessive consumption of sugar. RECENT FINDINGS: Appetite for sugar is propelled by changes in the morphology and activity of the reward system reminiscent of addiction. Sugar intake also shifts the hunger-satiety continuum, facilitating initiation of consumption in the absence of energy needs and maintenance of feeding despite ingestion of large food loads that endanger homeostasis. Ingestion of excessive amounts of sugar relies on triggering mechanisms that promote addictive-like behaviors, and on overriding neuroendocrine signals that protect internal milieu.

Palatability of Goat's versus Cow's Milk: Insights from the Analysis of Eating Behavior and Gene Expression in the Appetite-Relevant Brain Circuit in Laboratory Animal Models.

Goat's (GM) and cow's milk (CM) are dietary alternatives with select health benefits shown in human and animal studies. Surprisingly, no systematic analysis of palatability or preference for GM vs. CM has been performed to date. Here, we present a comprehensive investigation of short-term intake and palatability profiles of GM and CM in laboratory mice and rats. We studied consumption in no-choice and choice scenarios, including meal microstructure, and by using isocaloric milks and milk-enriched solid diets. Feeding results are accompanied by qPCR data of relevant genes in the energy balance-related hypothalamus and brain stem, and in the nucleus accumbens, which regulates eating for palatability. We found that GM and CM are palatable to juvenile, adult, and aged rodents. Given a choice, animals prefer GM- to CM-based diets. Analysis of meal microstructure using licking patterns points to enhanced palatability of and, possibly, greater motivation toward GM over CM. Most profound changes in gene expression after GM vs. CM were associated with the brain systems driving consumption for reward. We conclude that, while both GM and CM are palatable, GM is preferred over CM by laboratory animals, and this preference is driven by central mechanisms controlling eating for pleasure.

Seroprevalence of heartworm infection, risk factors for seropositivity, and frequency of prescribing heartworm preventives for cats in the United States and Canada.

OBJECTIVE To determine the seroprevalence of heartworm infection, risk factors for seropositivity, and frequency of prescribing heartworm preventives for cats. DESIGN Prospective cross-sectional study. ANIMALS 34,975 cats from 1,353 veterinary clinics (n = 26,707) and 125 animal shelters (8,268) in the United States and Canada. PROCEDURES Blood samples were collected from all cats and tested with a point-of-care ELISA for Dirofilaria immitis antigen, FeLV antigen, and FIV antibody. Results were compared among geographic regions and various cat groupings. RESULTS Seropositivity for heartworm antigen in cats was identified in 35 states but not in Canada; overall seroprevalence in the United States was 0.4%. Seroprevalence of heartworm infection was highest in the southern United States. A 3-fold increase in the proportion of seropositive cats was identified for those with (vs without) outdoor access, and a 2.5-fold increase was identified for cats that were unhealthy (vs healthy) when tested. Seroprevalence was 0.3% in healthy cats, 0.7% in cats with oral disease, 0.9% in cats with abscesses or bite wounds, and 1.0% in cats with respiratory disease. Coinfection with a retrovirus increased the risk of heartworm infection. Heartworm preventives were prescribed for only 12.6% of cats at testing, and prescribing was more common in regions with a higher seroprevalence. CONCLUSIONS AND CLINICAL RELEVANCE At an estimated prevalence of 0.4%, hundreds of thousands of cats in the United States are likely infected with heartworms. Given the difficulty in diagnosing infection at all clinically relevant parasite stages and lack of curative treatment options, efforts should be increased to ensure all cats receive heartworm preventives.

Seroprevalences of feline leukemia virus and feline immunodeficiency virus infection in cats in the United States and Canada and risk factors for seropositivity.

OBJECTIVE To estimate seroprevalences for FeLV antigen and anti-FIV antibody and risk factors for seropositivity among cats in the United States and Canada. DESIGN Cross-sectional study. ANIMALS 62,301 cats tested at 1,396 veterinary clinics (n = 45,406) and 127 animal shelters (16,895). PROCEDURES Blood samples were tested with a point-of-care ELISA for FeLV antigen and anti-FIV antibody. Seroprevalence was estimated, and risk factors for seropositivity were evaluated with bivariate and multivariable mixed-model logistic regression analyses adjusted for within-clinic or within-shelter dependencies. RESULTS Overall, seroprevalence was 3.1% for FeLV antigen and 3.6% for anti-FIV antibody. Adult age, outdoor access, clinical disease, and being a sexually intact male were risk factors for seropositivity for each virus. Odds of seropositivity for each virus were greater for cats tested in clinics than for those tested in shelters. Of 1,611 cats with oral disease, 76 (4.7%) and 157 (9.7%) were seropositive for FeLV and FIV, respectively. Of 4,835 cats with respiratory disease, 385 (8.0%) were seropositive for FeLV and 308 (6.4%) were seropositive for FIV. Of 1,983 cats with abscesses or bite wounds, 110 (5.5%) and 247 (12.5%) were seropositive for FeLV and FIV, respectively. Overall, 2,368 of 17,041 (13.9%) unhealthy cats were seropositive for either or both viruses, compared with 1,621 of 45,260 (3.6%) healthy cats. CONCLUSIONS AND CLINICAL RELEVANCE Seroprevalences for FeLV antigen and anti-FIV antibody were similar to those reported in previous studies over the past decade. Taken together, these results indicated a need to improve compliance with existing guidelines for management of feline retroviruses.

Growth and properties of coherent twinning superlattice nanowires.

Although coherent twin boundaries require little energy to form in nanoscale single crystals, their influence on properties can be dramatic. In recent years, some important steps forward have been made in understanding and controlling twinning processes at the nanoscale, making possible the fabrication of nanoengineered twinning superlattices in crystalline nanowires. These advances have opened new possibilities for properties and functionalities at the atomic and quantum scales by modulating twin densities. This article presents a brief overview of recent theoretical and experimental progress in growth mechanisms and promising properties of coherent twinning superlattice nanowires with special emphasis toward cubic systems in semiconductor and metallic materials. In particular, we show how nanoscale growth twins can considerably enhance bandgap engineering and mechanical behaviour in quasi-one-dimensional materials. Opportunities for future research in this emerging area are also discussed.