Purpose The purpose of this study was to compare the forearm supination and elbow flexion strength of the upper extremity in patients who have had an arthroscopic long head of the biceps tendon ...(LHBT) release with patients who have had an LHBT tenodesis. Methods Cybex isokinetic strength testing (Cybex Division of Lumex, Ronkonkoma, NY) was performed on 17 patients who underwent arthroscopic LHBT tenotomy, 19 patients who underwent arthroscopic LHBT tenodesis, and 31 age-, gender-, and body mass index–matched control subjects. Subjects were considered fully recovered from shoulder surgery, were released for unrestricted activities, and were at least 6 months after surgery before testing. Subjects were tested for forearm supination and elbow flexion strength of both arms by use of a Cybex II NORM isokinetic dynamometer at 60°/s and 120°/s. Testing was performed on injured and uninjured arms as well as dominant and nondominant arms in control subjects. Both forearm supination and elbow flexion strength values were recorded. Results Comparison between the involved and uninvolved upper extremities within each group by use of a paired t test showed a 7% increase in elbow flexion strength when the dominant and nondominant arms were compared at 60°/s. Neither the tenotomy nor tenodesis groups exhibited elbow flexion strength differences at 120°/s (all P ≥ .147). Comparison between groups by use of 2 × 3 analysis of variance (speed × group) showed no statistical difference in either forearm supination or elbow flexion strength when we compared the tenotomy, tenodesis, and control groups. Conclusions In asymptomatic patients who have had biceps tenotomy or tenodesis, no statistically significant forearm supination or elbow flexion strength differences existed in the involved extremity between the 2 study groups. Level of Evidence Level III, case-control study.
Microorganisms form biofilms containing differentiated cell populations. To determine factors driving differentiation, we herein visualize protein and metal distributions within Pseudomonas ...aeruginosa biofilms using imaging mass spectrometry. These in vitro experiments reveal correlations between differential protein distribution and metal abundance. Notably, zinc- and manganese-depleted portions of the biofilm repress the production of anti-staphylococcal molecules. Exposure to calprotectin (a host protein known to sequester metal ions at infectious foci) recapitulates responses occurring within metal-deplete portions of the biofilm and promotes interaction between P. aeruginosa and Staphylococcus aureus. Consistent with these results, the presence of calprotectin promotes co-colonization of the murine lung, and polymicrobial communities are found to co-exist in calprotectin-enriched airspaces of a cystic fibrosis lung explant. These findings, which demonstrate that metal fluctuations are a driving force of microbial community structure, have clinical implications because of the frequent occurrence of P. aeruginosa and S. aureus co-infections.
Borenium does it direct: A boron analogue of the Friedel–Crafts reaction uses inexpensive catecholatoborenium cations that are sufficiently electrophilic to borylate arenes by electrophilic aromatic ...substitution. The direct arene borylation proceeds with high regioselectivity for a range of anilines, N‐heterocycles, and thiophenes. Subsequent one‐pot transesterification provides the synthetically useful pinacol boronate esters (see scheme).
Abstract Progressive supranuclear palsy (PSP) is the most common atypical parkinsonian disorder. Abnormal tau inclusions, in selected regions of the brain, are a hallmark of the disease and the H1 ...haplotype of MAPT , the gene encoding tau, is the major risk factor in PSP. A 3-repeat and 4-repeat (4R) tau isoform ratio imbalance has been strongly implicated as a cause of disease. Thus, understanding tau isoform regional expression in disease and pathology-free states is crucial to elucidating the mechanisms involved in PSP and other tauopathies. We used a tau isoform-specific fluorescent assay to investigate relative 4R-tau expression in 6 different brain regions in PSP cases and healthy control samples. We identified a marked difference in 4R-tau relative expression, across brain regions and between MAPT haplotypes. Highest 4R-tau expression levels were identified in the globus pallidus compared with pons, cerebellum, and frontal cortex. 4R-tau expression levels were related to the MAPT H1 and H1c haplotypes. Similar regional variation was seen in PSP case and in control samples.
Groundwater is not a sustainable resource, unless ion is balanced by recharge. Identifying the sources of recharge in a groundwater basin is critical for sustainable groundwater management. We ...studied the importance of river water recharge to groundwater in the south‐eastern San Joaquin Valley (24,000 km2, population 4 million). We combined dissolved noble gas concentrations, stable isotopes, tritium, and carbon‐14 analyses to analyse the sources, mechanisms, and timescales of groundwater recharge. Area‐representative groundwater sampling and numerical model input data enabled a stable isotope mass balance and quantitative estimates of river and local recharge. River recharge, identified by a lighter stable isotope signature, represents 47 ± 4% of modern groundwater in the San Joaquin Valley (recharged after 1950) but only 26 ± 4% of premodern groundwater (recharged before 1950). This implies that the importance of river water recharge in the San Joaquin valley has nearly doubled and is likely the result of a 40% increase in total recharge, caused by river water irrigation return flows and increased stream depletion and river recharge due to groundwater pumping. Compared with the large and long‐duration capacity for water storage in the subsurface, storage of water in rivers is limited in time and volume, as evidenced by cold river recharge temperatures resulting from fast infiltration and recharge. Groundwater banking of seasonal surface water flows and expansion of managed aquifer recharge practices therefore appear to be a natural and promising method for increasing the resilience of the San Joaquin Valley water supply system.
Direct electrophilic borylation using Y2BCl (Y2 = Cl2 or o-catecholato) with equimolar AlCl3 and a tertiary amine has been applied to a wide range of arenes and heteroarenes. In situ ...functionalization of the ArBCl2 products is possible with TMS2MIDA, to afford bench-stable and easily isolable MIDA-boronates in moderate to good yields. According to a combined experimental and computational study, the borylation of activated arenes at 20 °C proceeds through an SEAr mechanism with borenium cations, Y2B(amine)+, the key electrophiles. For catecholato-borocations, two amine dependent reaction pathways were identified: (i) With CatB(NEt3)+, an additional base is necessary to accomplish rapid borylation by deprotonation of the borylated arenium cation (σ complex), which otherwise would rather decompose to the starting materials than liberate the free amine to effect deprotonation. Apart from amines, the additional base may also be the arene itself when it is sufficiently basic (e.g., N-Me-indole). (ii) When the amine component of the borocation is less nucleophilic (e.g., 2,6-lutidine), no additional base is required due to more facile amine dissociation from the boron center in the borylated arenium cation intermediate. Borenium cations do not borylate poorly activated arenes (e.g., toluene) even at high temperatures; instead, the key electrophile in this case involves the product from interaction of AlCl3 with Y2BCl. When an extremely bulky amine is used, borylation again does not proceed via a borenium cation; instead, a number of mechanisms are feasible including via a boron electrophile generated by coordination of AlCl3 to Y2BCl, or by initial (heteroarene)AlCl3 adduct formation followed by deprotonation and transmetalation.
Uranium isotopic composition can provide valuable information about the history and provenance of a nuclear material; therefore, uranium isotopic analyses are frequently made in the nuclear ...forensics, safeguards, and environmental monitoring communities. These measurements have always presented challenges due to the extreme variability in the relative abundance between the major (235U, 238U) and minor (233U, 234U, 236U) isotopes of uranium. The recently developed ATONA (Atto- to Nano-Amp) amplification system paired with Faraday cup detectors has a large dynamic range and low noise floor making it ideal for measuring uranium isotopic ratios in materials of both natural and anthropogenic origin. A wide variety of certified reference materials were analyzed to investigate the utility of the ATONA amplification system for determining uranium isotopic composition in samples ranging from depleted to highly enriched. The ATONA amplifiers provide nearly an order of magnitude improvement in external reproducibility over 1011 Ω amplifiers when measuring the minor 234U/238U ratio in isotopically natural and depleted samples and when paired with a secondary electron multiplier can measure very low relative abundance uranium isotopes (i.e., 236U).
Background Current etiologic theories concerning healing rates in rotator cuff repair have focused on the blood supply in the tendinous portion of the cuff. We currently have little information ...regarding the effect of our repair techniques on this critical variable. We hypothesize that intratendinous blood flow is changed during transosseus equivalent tendon fixation. Methods Eighteen consecutive patients with rotator cuff tears amenable to double row fixation were included in the study. Each patient underwent a standard arthroscopic transosseous equivalent double row fixation procedure using the Arthrex SutureBridge technique (Arthrex, Naples, FL, USA). After tying down of the medial row, a first set of recordings was taken using a custom laser doppler flowmetry probe (Perimed, Inc., Ohio, USA). A second recording was made following securing of the lateral PushLock anchors. The data were compared to determine the overall effect on blood flow associated with this technique. Results Summated averages for the 2 groups show a significant (44.67%) decline in the blood flow present after the second row of implants are placed ( P < .01). Individual calculations for regions of the cuff tear indicate significant differences in anterior third ( P = .01), middle third ( P < .01), and posterior third ( P = .02) of the tear after transosseous equivalent fixation. Conclusion Completion of the construct with lateral anchors in the transosseous equivalent technique results in reduced but preserved blood flow in the tendon repair site. Further study is required to determine the implications for tendon healing. Clinical relevance Intratendinous blood flow is a variable that should be considered when evaluating repair methods in rotator cuff surgery.
We experimentally demonstrate the direct coupling of silicate mineral dissolution with saline water electrolysis and H ₂ production to effect significant air CO ₂ absorption, chemical conversion, and ...storage in solution. In particular, we observed as much as a 10 ⁵-fold increase in OH ⁻ concentration (pH increase of up to 5.3 units) relative to experimental controls following the electrolysis of 0.25 M Na ₂SO ₄ solutions when the anode was encased in powdered silicate mineral, either wollastonite or an ultramafic mineral. After electrolysis, full equilibration of the alkalized solution with air led to a significant pH reduction and as much as a 45-fold increase in dissolved inorganic carbon concentration. This demonstrated significant spontaneous air CO ₂ capture, chemical conversion, and storage as a bicarbonate, predominantly as NaHCO ₃. The excess OH ⁻ initially formed in these experiments apparently resulted via neutralization of the anolyte acid, H ₂SO ₄, by reaction with the base mineral silicate at the anode, producing mineral sulfate and silica. This allowed the NaOH, normally generated at the cathode, to go unneutralized and to accumulate in the bulk electrolyte, ultimately reacting with atmospheric CO ₂ to form dissolved bicarbonate. Using nongrid or nonpeak renewable electricity, optimized systems at large scale might allow relatively high-capacity, energy-efficient (<300 kJ/mol of CO ₂ captured), and inexpensive (<$100 per tonne of CO ₂ mitigated) removal of excess air CO ₂ with production of carbon-negative H ₂. Furthermore, when added to the ocean, the produced hydroxide and/or (bi)carbonate could be useful in reducing sea-to-air CO ₂ emissions and in neutralizing or offsetting the effects of ongoing ocean acidification.
PDF
