The imaging properties and observation of the sterically regulated translational motion of discrete tungsten polyoxometalate Linqvist ions (i.e., [W(6)O(19)](2-)) within carbon nanotubes of specific internal diameter are reported. The translational motion of the nonspheroidal anion within the nanotube capillary is found to be impeded by its near-perfect accommodation to the internal van der Waals surface of the nanotube wall. Rotational motion of the anion about one remaining degree of freedom permits translational motion of the anion along the nanotube followed by locking in at sterically favorable positions in a mechanism similar to a molecular ratchet. This steric locking permits the successful direct imaging of the constituent octahedral cation template of individual [W(6)O(19)](2-) anions by high resolution transmission electron microscopy thereby permitting meterological measurements to be performed directly on the anion. Direct imaging of pairs of equatorial W(2) atoms within the anion reveal steric relaxation of the anion contained within the nanotube capillary relative to the bulk anion structure.

Clinicians can inform women that physical activity may be an effective treatment for primary dysmenorrhea but there is a need for high-quality trials before this can be confirmed.

Background Severe mental illness (SMI; schizophrenia, bipolar disorders (BDs), and other nonorganic psychoses) is associated with increased risk of cardiovascular disease (CVD) and CVD-related mortality. To date, no systematic review has investigated changes in population level CVD-related mortality over calendar time. It is unclear if this relationship has changed over time in higher-income countries with changing treatments. Methods and findings To address this gap, a systematic review was conducted, to assess the association between SMI and CVD including temporal change. Seven databases were searched (last: November 30, 2021) for cohort or case–control studies lasting ≥1 year, comparing frequency of CVD mortality or incidence in high-income countries between people with versus without SMI. No language restrictions were applied. Random effects meta-analyses were conducted to compute pooled hazard ratios (HRs) and rate ratios, pooled standardised mortality ratios (SMRs), pooled odds ratios (ORs), and pooled risk ratios (RRs) of CVD in those with versus without SMI. Temporal trends were explored by decade. Subgroup analyses by age, sex, setting, world region, and study quality (Newcastle–Ottawa scale (NOS) score) were conducted. The narrative synthesis included 108 studies, and the quantitative synthesis 59 mortality studies (with (≥1,841,356 cases and 29,321,409 controls) and 28 incidence studies (≥401,909 cases and 14,372,146 controls). The risk of CVD-related mortality for people with SMI was higher than controls across most comparisons, except for total CVD-related mortality for BD and cerebrovascular accident (CVA) for mixed SMI. Estimated risks were larger for schizophrenia than BD. Pooled results ranged from SMR = 1.55 (95% confidence interval (CI): 1.33 to 1.81, p < 0.001), for CVA in people with BD to HR/rate ratio = 2.40 (95% CI: 2.25 to 2.55, p < 0.001) for CVA in schizophrenia. For schizophrenia and BD, SMRs and pooled HRs/rate ratios for CHD and CVD mortality were larger in studies with outcomes occurring during the 1990s and 2000s than earlier decades (1980s: SMR = 1.14, 95% CI: 0.57 to 2.30, p = 0.71; 2000s: SMR = 2.59, 95% CI: 1.93 to 3.47, p < 0.001 for schizophrenia and CHD) and in studies including people with younger age. The incidence of CVA, CVD events, and heart failure in SMI was higher than controls. Estimated risks for schizophrenia ranged from HR/rate ratio 1.25 (95% CI: 1.04 to 1.51, p = 0.016) for total CVD events to rate ratio 3.82 (95% CI: 3.1 to 4.71, p < 0.001) for heart failure. Incidence of CHD was higher in BD versus controls. However, for schizophrenia, CHD was elevated in higher-quality studies only. The HR/rate ratios for CVA and CHD were larger in studies with outcomes occurring after the 1990s. Study limitations include the high risk of bias of some studies as they drew a comparison cohort from general population rates and the fact that it was difficult to exclude studies that had overlapping populations, although attempts were made to minimise this. Conclusions In this study, we found that SMI was associated with an approximate doubling in the rate ratio of CVD-related mortality, particularly since the 1990s, and in younger groups. SMI was also associated with increased incidence of CVA and CHD relative to control participants since the 1990s. More research is needed to clarify the association between SMI and CHD and ways to mitigate this risk.

BackgroundExercise is recommended as a treatment for premenstrual syndrome (PMS) in clinical guidelines, but this is currently based on poor-quality trial evidence.AimTo systematically review the evidence for the effectiveness of exercise as a treatment for PMS.Design & settingThis systematic review searched eight major databases, including MEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials (CENTRAL), and two trial registries from inception until April 2019.MethodRandomised controlled trials (RCTs) comparing exercise interventions of a minimum of 8-weeks duration with non-exercise comparator groups in women with PMS were included. Mean change scores for any continuous PMS outcome measure were extracted from eligible trials and standardised mean differences (SMDs) were calculated where possible. Random-effects meta-analysis of the effect of exercise on global PMS symptoms was the primary outcome. Secondary analyses examined the effects of exercise on predetermined clusters of psychological, physical, and behavioural symptoms.ResultsA total of 436 non-duplicate returns were screened, with 15 RCTs eligible for inclusion (n = 717). Seven trials contributed data to the primary outcome meta-analysis (n = 265); participants randomised to an exercise intervention reported reduced global PMS symptom scores (SMD = -1.08; 95% confidence interval [CI] = -1.88 to -0.29) versus comparator, but with substantial heterogeneity (I2 = 87%). Secondary results for psychological (SMD = -1.67; 95% CI = -2.38 to -0.96), physical (SMD = -1.62; 95% CI = -2.41 to -0.83) and behavioural (SMD = -1.94; 95% CI = -2.45 to -1.44) symptom groupings displayed similar findings. Most trials (87%) were considered at high risk of bias.ConclusionBased on current evidence, exercise may be an effective treatment for PMS, but some uncertainty remains.

Background: Primary dysmenorrhea is cramping abdominal pain associated with menses. It is prevalent, affects quality of life, and can cause absenteeism. Although evidence based medical treatment options exist, women may not tolerate these or may prefer to use non-medical treatments. Physical activity has been recommended by clinicians for primary dysmenorrhea since the 1930s, but its effectiveness is still unknown.Objective: We sought to determine the effectiveness of physical activity for the treatment of primary dysmenorrhea Data sources: Systematic literature searches of multiple databases were performed, including searches for grey literature, from database inception to 24 th May 2017.Google searches and citation searching of previous reviews was also conducted.Study eligibility criteria: Studies were selected using predefined selection criteria as specified in the registered protocol. Randomized controlled trials were included if they assessed physical activity interventions against any comparator over at least two menstrual cycles and assessed pain intensity or pain duration as an outcome. Study selection was performed by two independent reviewers at both the title/abstract and full text level. Study appraisal and synthesis methods:Study quality was assessed by two independent reviewers using the Cochrane Risk of Bias Tool. Random effects metaanalyses for pain intensity and pain duration were conducted, with pre-specified subgroup analysis by type of physical activity intervention.Results: Searches identified 15 eligible randomized controlled trials; totalling 1681 participants. Data from 11 studies was included in the meta-analyses. Pooled results demonstrated significant effect estimates for physical activity versus comparators for pain intensity (-1.89cm on Visual Analogue Scale, 95% confidence interval -2.96 to -1.09) and pain duration (-3.92 hours, 95% confidence interval -4.86, to -2.97).Heterogeneity for both these results was high and only partly mitigated by subgroup analysis. Primary studies were of low or moderate methodological quality but results for pain intensity remained stable during sensitivity analysis by study quality. Conclusion:Clinicians can inform women that physical activity may be an effective treatment for primary dysmenorrhea but there is a need for high quality trials before this can be confirmed.