A 26-Year-Old Man with Sternoclavicular Arthritis

A 26-year-old man presented to a hospital in Lima, Peru, with a two-week history of fever, myalgias, and arthralgia of the left hip and right sternoclavicular joint. The authors discuss the work up, diagnosis, and management

The History and Conservation of Saltpeter Works in Mammoth Cave, Kentucky

Remains of the saltpeter mining operation in Mammoth Cave are a significant feature of several cave tours and figure prominently in the history of cave use. We undertook a comprehensive review of existing historical descriptions and recent archaeological investigations to construct the most reasonable account of how the saltpeter operation worked and assess its current conditions. At least three types of saltpeter vats were constructed in the cave reflecting an increase in the size of the operation and efficiency of processing sediments over time. Remains of three pump towers are also found in the cave in various states of preservation. The water pipe system was mostly dismantled, but archaeological evidence indicates its most probable route through the cave. We recommend more thorough documentation of existing remains, conservation efforts to preserve existing remains, better interpretative signage, and possibly repair or replication of damaged or missing components to further enhance public interpretation

Emergence of low-symmetry foldamers from single monomers

Self-assembly is a powerful method to obtain large discrete functional molecular architectures. When using a single building block, self-assembly generally yields symmetrical objects in which all the subunits relate similarly to their neighbours. Here we report the discovery of a family of self-constructing cyclic macromolecules with stable folded conformations of low symmetry, which include some with a prime number (13, 17 and 23) of units, despite being formed from a single component. The formation of these objects amounts to the production of polymers with a perfectly uniform length. Design rules for the spontaneous emergence of such macromolecules include endowing monomers with a strong potential for non-covalent interactions that remain frustrated in competing entropically favoured yet conformationally restrained smaller cycles. The process can also be templated by a guest molecule that itself has an asymmetrical structure, which paves the way to molecular imprinting techniques at the level of single polymer chains

Progression of Age-Related Macular Degeneration Among Individuals Homozygous for Risk Alleles on Chromosome 1 (CFH-CFHR5) or Chromosome 10 (ARMS2/HTRA1) or Both

Importance: Age-related macular degeneration (AMD) is a common cause of irreversible vision loss among individuals older than 50 years. Although considerable advances have been made in our understanding of AMD genetics, the differential effects of major associated loci on disease manifestation and progression may not be well characterized. Objective: To elucidate the specific associations of the 2 most common genetic risk loci for AMD, the CFH-CFHR5 locus on chromosome 1q32 (Chr1) and the ARMS2/HTRA1 locus on chromosome 10q26 (Chr10)-independent of one another and in combination-with time to conversion to late-stage disease and to visual acuity loss. Design, Setting, and Participants: This case series study included 502 individuals who were homozygous for risk variants at both Chr1 and Chr10 (termed Chr1&10-risk) or at either Chr1 (Chr1-risk) or Chr10 (Chr10-risk) and who had enrolled in Genetic and Molecular Studies of Eye Diseases at the Sharon Eccles Steele Center for Translational Medicine between September 2009 and March 2020. Multimodal imaging data were reviewed for AMD staging, including grading of incomplete and complete retinal pigment epithelium and outer retinal atrophy. Main Outcomes and Measures: Hazard ratios and survival times for conversion to any late-stage AMD, atrophic or neovascular, and associated vision loss of 2 or more lines. Results: In total, 317 participants in the Chr1-risk group (median [IQR] age at first visit, 75.6 [69.5-81.7] years; 193 women [60.9%]), 93 participants in the Chr10-risk group (median [IQR] age at first visit, 77.5 [72.2-84.2] years; 62 women [66.7%]), and 92 participants in the Chr1&10-risk group (median [IQR] age at first visit, 71.7 [68.0-76.3] years; 62 women [67.4%]) were included in the analyses. After adjusting for age and AMD grade at first visit, compared with 257 participants in the Chr1-risk group, 56 participants in the Chr1&10-risk group (factor of 3.3 [95% CI, 1.6-6.8]; P < .001) and 58 participants in the Chr10-risk group (factor of 2.6 [95% CI, 1.3-5.2]; P = .007) were more likely to convert to a late-stage phenotype during follow-up. This difference was mostly associated with conversion to macular neovascularization, which occurred earlier in participants with Chr1&10-risk and Chr10-risk. Eyes in the Chr1&10-risk group (median [IQR] survival, 5.7 [2.1-11.1] years) were 2.1 (95% CI, 1.1-3.9; P = .03) times as likely and eyes in the Chr10-risk group (median [IQR] survival, 6.3 [2.7-11.3] years) were 1.8 (95% CI, 1.0-3.1; P = .05) times as likely to experience a visual acuity loss of 2 or more lines compared with eyes of the Chr1-risk group (median [IQR] survival, 9.4 [4.1-* (asterisk indicates event rate did not reach 75%)] years). Conclusions and Relevance: These findings suggest differential associations of the 2 major AMD-related risk loci with structural and functional disease progression and suggest distinct underlying biological mechanisms associated with these 2 loci. These genotype-phenotype associations may warrant consideration when designing and interpreting AMD research studies and clinical trials

Single-step hydrogen production from NH3, CH4, and biogas in stacked proton ceramic reactors

Proton ceramic reactors offer efficient extraction of hydrogen from ammonia, methane, and biogas by coupling endothermic reforming reactions with heat from electrochemical gas separation and compression. Preserving this efficiency in scale-up from cell to stack level poses challenges to the distribution of heat and gas flows and electric current throughout a robust functional design. Here, we demonstrate a 36-cell well-balanced reactor stack enabled by a new interconnect that achieves complete conversion of methane with more than 99% recovery to pressurized hydrogen, leaving a concentrated stream of carbon dioxide. Comparable cell performance was also achieved with ammonia, and the operation was confirmed at pressures exceeding 140 bars. The stacking of proton ceramic reactors into practical thermo-electrochemical devices demonstrates their potential in efficient hydrogen production.This work was supported by Norway’s Ministry of Petroleum and Energy through the Gassnova project CLIMIT grant 618191 in partnership with Engie SA, Equinor, ExxonMobil, Saudi Aramco, Shell, and TotalEnergies and the Research Council of Norway NANO2021 project DynaPro grant 296548

A River Continuum Analysis of an Anthropogenically-Impacted System: The Little Bear River, Utah

In September 2012 the Aquatic Ecology Practicum class from Utah State University studied the 51km river continuum of the Little Bear River located in northern Utah (Figure 1). The relatively pristine headwaters of the river begin in the Wasatch Mountain Range at an altitude of 1800 m. The river flows northward into Cache Valley where it terminates in Cutler Reservoir (1345 m elevation). Agricultural development and urbanization have modified the natural terrain and chemical characteristics of the river, and Hyrum Reservoir, located midway along the gradient causes a discontinuity in river processes. The results from analyses of stream condition indicators from up to eleven stations along the gradient were interpreted within the context of the River Continuum Concept (Vannote et al. 1980) and the Serial Discontinuity Hypothesis (Ward and Stanford 1983)