Arabidopsis stromal carbonic anhydrases exhibit non-overlapping roles in photosynthetic efficiency and development.

Carbonic anhydrases (CAs) are ubiquitous enzymes that accelerate the reversible conversion of CO2 to HCO3 - . The Arabidopsis genome encodes members of the α-, ß- and γ-CA families, and it has been hypothesized that ßCA activity has a role in photosynthesis. In this work, we tested this hypothesis by characterizing the two plastidial ßCAs, ßCA1 and ßCA5, in physiological conditions of growth. We conclusively established that both proteins are localized in the chloroplast stroma and that the loss of ßCA5 induced the expression of ßCA1, supporting the existence of regulatory mechanisms to control the expression of stromal ßCAs. We also established that ßCA1 and ßCA5 have markedly different enzymatic kinetics and physiological relevance. Specifically, we found that ßCA5 had a first-order rate constant ~10-fold lower than ßCA1, and that the loss of ßCA5 is detrimental to growth and could be rescued by high CO2 . Furthermore, we established that, while a ßCA1 mutation showed near wild-type growth and no significant impact on photosynthetic efficiency, the loss of ßCA5 markedly disrupted photosynthetic efficiency and light-harvesting capacity at ambient CO2 . Therefore, we conclude that in physiological autotrophic growth, the loss of the more highly expressed ßCA1 does not compensate for the loss of a less active ßCA5, which in turn is involved in growth and photosynthesis at ambient CO2 levels. These results lend support to the hypothesis that, in Arabidopsis,ßCAs have non-overlapping roles in photosynthesis and identify a critical activity of stromal ßCA5 and a dispensable role for ßCA1.

Clinical Characteristics, Health Care Utilization, and Outcomes Among Patients in a Pilot Surveillance System for Invasive Mold Disease-Georgia, United States, 2017-2019.

Background: Invasive mold diseases (IMDs) cause severe illness, but public health surveillance data are lacking. We describe data collected from a laboratory-based, pilot IMD surveillance system. Methods: During 2017-2019, the Emerging Infections Program conducted active IMD surveillance at 3 Atlanta-area hospitals. We ascertained potential cases by reviewing histopathology, culture, and Aspergillus galactomannan results and classified patients as having an IMD case (based on European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and the National Institute of Allergy and Infectious Diseases Mycoses Study Group [MSG] criteria) or a non-MSG IMD case (based on the treating clinician's diagnosis and use of mold-active antifungal therapy). We described patient features and compared patients with MSG vs non-MSG IMD cases. Results: Among 304 patients with potential IMD, 104 (34.2%) met an IMD case definition (41 MSG, 63 non-MSG). The most common IMD types were invasive aspergillosis (n = 66 [63.5%]), mucormycosis (n = 8 [7.7%]), and fusariosis (n = 4 [3.8%]); the most frequently affected body sites were pulmonary (n = 66 [63.5%]), otorhinolaryngologic (n = 17 [16.3%]), and cutaneous/deep tissue (n = 9 [8.7%]). Forty-five (43.3%) IMD patients received intensive care unit-level care, and 90-day all-cause mortality was 32.7%; these outcomes did not differ significantly between MSG and non-MSG IMD patients. Conclusions: IMD patients had high mortality rates and a variety of clinical presentations. Comprehensive IMD surveillance is needed to assess emerging trends, and strict application of MSG criteria for surveillance might exclude over one-half of clinically significant IMD cases.

Comparison of nanostructure and nanomechanical properties of cast and air sides of polyimide films from different manufacturers.

Polyimide films are widely applied in harsh environments because of their outstanding performance. High-quality polyimide films are often manufactured through a two-step process. The complicated procedure results in different properties on the two sides, i.e., the air side and cast side of the films, and the quality of products from different manufacturers varies notably. In the present work, polyimide films with two thicknesses (1 and 2 mm) from four manufacturers were investigated. Atomic force microscope and FT-IR spectrometer were employed to monitor morphology, roughness, nanomechanical properties, and corresponding relative imidization degree on the two sides of each film. Statistical tools were applied to analyze the data. T-test suggests that the two sides of the same film were significantly different in roughness, DMT modulus, and relative imidization degree (p < 0.05). The roughness on the air side was consistently smaller than that of the cast side. ANOVA was used to compare differences among the manufacturers. Manufacturer B provided the smoothest films with the highest DMT moduli and imidization degrees. A positive correlation was found between the DMT modulus and imidization degree (r = 0.7330). Nanostructure and nanomechanical properties could affect the quality of the film. Striped morphology and adhesion were found on the cast side of the 2-mm film from manufacturer D, which compromised the film tension in the direction perpendicular to the strips. Investigations of morphology and mechanical properties of polyimide film at the nanoscale would help us better characterize the film, assure its quality, and select suitable film and side for proper applications.