Adjunctive Dorsal Spanning Plate Fixation in the Stabilization of Perilunate Dislocations.

PURPOSE: To compare the biomechanical properties of adjunctive dorsal spanning plate (DSP) fixation with traditional K-wire fixation of perilunate dislocations in a cadaveric model. METHODS: Fourteen fresh-frozen cadaveric wrists underwent simulated perilunate injury. The specimens were randomly allocated to either K-wire fixation versus K-wire and DSP fixation. Scapholunate (SL) ligament repair was performed in all specimens. The constructs were tested using a robot cyclically and to failure. Fluoroscopic images were obtained of the specimens prior to simulated injury, after fixation, after 10 and 100 loading cycles, and at construct failure. Differences in carpal alignment parameters (SL interval, SL angle, lunotriquetral interval, and capitolunate angle) and load to failure were recorded. RESULTS: There were no statistically significant differences between the two group's carpal alignment parameters after fixation. Specimens fixated with K-wires and DSP required significantly higher loads to achieve construct failure. The only significant difference between the two groups' carpal alignment parameters was SL interval change at failure. CONCLUSIONS: Compared with K-wire fixation alone, adjunctive DSP fixation resulted in significantly increased loads to failure and decreased change in SL interval at the time of failure. CLINICAL RELEVANCE: Adjunctive DSP may be a useful technique in the polytraumatized patient in whom providing back a weight-bearing extremity may be advantageous in the rehabilitation process.

Drainage Pattern of Craniofacial Veins With Emphasis on its Influence on Facial Reconstruction Procedures.

As the facial transplantation procedures are becoming more popular and frequent in recent years, for repairing facial trauma, variations in the veins of head and neck needs to be reported time and again. This study was undertaken to examine the course and drainage pattern of the facial vein and external jugular vein on this context and emphasize its surgical implications. The authors studied the head and neck region of 50 embalmed cadavers of both sexes to document normal and variant anatomy of facial, retromandibular, and external jugular veins. In 30% of the head and neck regions, different draining pattern of the above-mentioned veins were observed. One of the rare variation discovered was the splitting of the retromandibular vein to embrace the external carotid artery within the parotid gland. The data about variations in the termination of facial vein, retromandibular vein, and external jugular vein, as observed in the present study might be useful in avoiding accidental injury to these vessels during any surgical intervention in the face as well as neck. Level of Evidence: IV.

Lung infections in immunocompromised children.

Pulmonary infection is the leading cause of infectious morbidity and mortality in children with immune defects. We provide a comprehensive review of lung infections in immunocompromised children, with a focus on imaging findings and imaging-based management. We include an overview of the immune defences of the respiratory tract, the aetiologies of immune defects in children, the features of specific infections and important differential diagnoses and describe diagnostic strategies using imaging and non-imaging-based techniques.

Do Patients Living in Rural Areas Report Inferior 1-Year Outcomes After Total Knee Arthroplasty? A Matched Cohort Analysis.

BACKGROUND: Rural status has been associated with poor outcomes for several health problems, but its relationship and outcomes following total knee arthroplasty (TKA) has not been fully characterized. Patient-reported outcomes (PROs) are key measures of success following TKA. Therefore, this matched cohort study was designed to test the hypothesis that patients who live in rural settings will report significantly worse PRO scores 1 year after TKA when compared to those who live in urban or suburban settings. METHODS: Patients undergoing TKA at our institution were categorized into urban, suburban, and rural cohorts based on Rural Urban Commuting Area scores using reported living setting zip codes. Cohorts were matched for body mass index classification. Demographic data were extracted from the medical records, and PRO data (Knee Injury and Osteoarthritis Outcome Score, Joint Replacement (KOOS JR), Patient-Reported Outcomes Measurement Information System (PROMIS) Global Health and Mental Health, University of California, Los Angeles (UCLA) Activity Score, and Visual Analog Scale Pain were collected preoperatively and 1-year postoperatively. Comparisons across living settings were made using analysis of variance (ANOVA) tests or Chi-square tests. A total of 882 TKA patients (n = 294 per cohort) were analyzed. RESULTS: Patients living in urban areas had significantly lower preoperative pain scores compared to suburban and rural residents. All measured PROs significantly improved from preoperative levels at 1 year post-TKA with no significant differences among living setting cohorts. CONCLUSIONS: In cohorts matched for body mass index, living in a rural setting was not associated with inferior PROs 1 year after TKA. LEVEL OF EVIDENCE: Level 4, retrospective cohort study.

Selective Enhancer Dependencies in MYC -Intact and MYC -Rearranged Germinal Center B-cell Diffuse Large B-cell Lymphoma.

High expression of MYC and its target genes define a subset of germinal center B-cell diffuse large B-cell lymphoma (GCB-DLBCL) associated with poor outcomes. Half of these high-grade cases show chromosomal rearrangements between the MYC locus and heterologous enhancer-bearing loci, while focal deletions of the adjacent non-coding gene PVT1 are enriched in MYC -intact cases. To identify genomic drivers of MYC activation, we used high-throughput CRISPR-interference (CRISPRi) profiling of candidate enhancers in the MYC locus and rearrangement partner loci in GCB-DLBCL cell lines and mantle cell lymphoma (MCL) comparators that lacked common rearrangements between MYC and immunoglobulin (Ig) loci. Rearrangements between MYC and non-Ig loci were associated with unique dependencies on specific enhancer subunits within those partner loci. Notably, fitness dependency on enhancer modules within the BCL6 super-enhancer ( BCL6 -SE) cluster regulated by a transcription factor complex of MEF2B, POU2F2, and POU2AF1 was higher in cell lines bearing a recurrent MYC::BCL6 -SE rearrangement. In contrast, GCB-DLBCL cell lines without MYC rearrangement were highly dependent on a previously uncharacterized 3' enhancer within the MYC locus itself (GCBME-1), that is regulated in part by the same triad of factors. GCBME-1 is evolutionarily conserved and active in normal germinal center B cells in humans and mice, suggesting a key role in normal germinal center B cell biology. Finally, we show that the PVT1 promoter limits MYC activation by either native or heterologous enhancers and demonstrate that this limitation is bypassed by 3' rearrangements that remove PVT1 from its position in cis with the rearranged MYC gene. Key points: CRISPR-interference screens identify a conserved germinal center B cell MYC enhancer that is essential for GCB-DLBCL lacking MYC rearrangements. Functional profiling of MYC partner loci reveals principles of MYC enhancer-hijacking activation by non-immunoglobulin rearrangements.

The Curiosity Rover's Exploration of Glen Torridon, Gale Crater, Mars: An Overview of the Campaign and Scientific Results.

The Mars Science Laboratory rover, Curiosity, explored the clay mineral-bearing Glen Torridon region for 1 Martian year between January 2019 and January 2021, including a short campaign onto the Greenheugh pediment. The Glen Torridon campaign sought to characterize the geology of the area, seek evidence of habitable environments, and document the onset of a potentially global climatic transition during the Hesperian era. Curiosity roved 5 km in total throughout Glen Torridon, from the Vera Rubin ridge to the northern margin of the Greenheugh pediment. Curiosity acquired samples from 11 drill holes during this campaign and conducted the first Martian thermochemolytic-based organics detection experiment with the Sample Analysis at Mars instrument suite. The lowest elevations within Glen Torridon represent a continuation of lacustrine Murray formation deposits, but overlying widespread cross bedded sandstones indicate an interval of more energetic fluvial environments and prompted the definition of a new stratigraphic formation in the Mount Sharp group called the Carolyn Shoemaker formation. Glen Torridon hosts abundant phyllosilicates yet remains compositionally and mineralogically comparable to the rest of the Mount Sharp group. Glen Torridon samples have a great diversity and abundance of sulfur-bearing organic molecules, which are consistent with the presence of ancient refractory organic matter. The Glen Torridon region experienced heterogeneous diagenesis, with the most striking alteration occurring just below the Siccar Point unconformity at the Greenheugh pediment. Results from the pediment campaign show that the capping sandstone formed within the Stimson Hesperian aeolian sand sea that experienced seasonal variations in wind direction.

Mission Overview and Scientific Contributions from the Mars Science Laboratory Curiosity Rover After Eight Years of Surface Operations.

NASA's Mars Science Laboratory mission, with its Curiosity rover, has been exploring Gale crater (5.4° S, 137.8° E) since 2012 with the goal of assessing the potential of Mars to support life. The mission has compiled compelling evidence that the crater basin accumulated sediment transported by marginal rivers into lakes that likely persisted for millions of years approximately 3.6 Ga ago in the early Hesperian. Geochemical and mineralogical assessments indicate that environmental conditions within this timeframe would have been suitable for sustaining life, if it ever were present. Fluids simultaneously circulated in the subsurface and likely existed through the dry phases of lake bed exposure and aeolian deposition, conceivably creating a continuously habitable subsurface environment that persisted to less than 3 Ga in the early Amazonian. A diversity of organic molecules has been preserved, though degraded, with evidence for more complex precursors. Solid samples show highly variable isotopic abundances of sulfur, chlorine, and carbon. In situ studies of modern wind-driven sediment transport and multiple large and active aeolian deposits have led to advances in understanding bedform development and the initiation of saltation. Investigation of the modern atmosphere and environment has improved constraints on the timing and magnitude of atmospheric loss, revealed the presence of methane and the crater's influence on local meteorology, and provided measurements of high-energy radiation at Mars' surface in preparation for future crewed missions. Rover systems and science instruments remain capable of addressing all key scientific objectives. Emphases on advance planning, flexibility, operations support work, and team culture have allowed the mission team to maintain a high level of productivity in spite of declining rover power and funding. Supplementary Information: The online version contains supplementary material available at 10.1007/s11214-022-00882-7.

Functional consequences of postnatal interventions in a mouse model of Fragile X syndrome.

BACKGROUND: Fragile X syndrome (FXS) is a leading genetic cause of autism and intellectual disability with cortical hyperexcitability and sensory hypersensitivity attributed to loss and hypofunction of inhibitory parvalbumin-expressing (PV) cells. Our studies provide novel insights into the role of excitatory neurons in abnormal development of PV cells during a postnatal period of inhibitory circuit refinement. METHODS: To achieve Fragile X mental retardation gene (Fmr1) deletion and re-expression in excitatory neurons during the postnatal day (P)14-P21 period, we generated CreCaMKIIa/Fmr1Flox/y (cOFF) and CreCaMKIIa/Fmr1FloxNeo/y (cON) mice, respectively. Cortical phenotypes were evaluated in adult mice using biochemical, cellular, clinically relevant electroencephalogram (EEG) and behavioral tests. RESULTS: We found that similar to global Fmr1 KO mice, the density of PV-expressing cells, their activation, and sound-evoked gamma synchronization were impaired in cOFF mice, but the phenotypes were improved in cON mice. cOFF mice also showed enhanced cortical gelatinase activity and baseline EEG gamma power, which were reduced in cON mice. In addition, TrkB phosphorylation and PV levels were lower in cOFF mice, which also showed increased locomotor activity and anxiety-like behaviors. Remarkably, when FMRP levels were restored in only excitatory neurons during the P14-P21 period, TrkB phosphorylation and mouse behaviors were also improved. CONCLUSIONS: These results indicate that postnatal deletion or re-expression of FMRP in excitatory neurons is sufficient to elicit or ameliorate structural and functional cortical deficits, and abnormal behaviors in mice, informing future studies about appropriate treatment windows and providing fundamental insights into the cellular mechanisms of cortical circuit dysfunction in FXS.

Serious health-related suffering and palliative care in South Asian countries.

PURPOSE OF REVIEW: South Asia, with a population of 1.79 billion, has close to 9.9 million individuals experiencing serious health-related suffering (SHS). South Asia accounts for 10.23% of the world's cancer incidence. The prevalence of cancer mortality in the region is 68.44%, significantly higher than the world average of 59.74%. This poor outcome highlights the need to focus on SHS in the region. This review was undertaken to assess the current status of palliative care inequities in the region and to guide future action. RECENT FINDINGS: Using morphine-equivalent doses of opioid analgesics (excluding methadone) per cancer death as a proxy measure for access to palliative care, the International Narcotics Control Board data in 2020 show poor access to palliative care. Less than 4% of those in need are able to access palliative care in India, whereas in Afghanistan only 0.2% have access. Inappropriate end-of-life care (EOLC) and catastrophic out-of-pocket health expenditure compound the problem. SUMMARY: The solutions involve the introduction of national programs for palliative care, demonstration of culturally appropriate best practices as proof of concept, favourable legislation for medical opioid access, community participation, engagement of civil society to improve awareness, inclusion of palliative and adding EOLC to medical education and need-based research. VIDEO ABSTRACT: http://links.lww.com/COSPC/A30.

Neratinib-Plus-Cetuximab in Quadruple-WT (KRAS, NRAS, BRAF, PIK3CA) Metastatic Colorectal Cancer Resistant to Cetuximab or Panitumumab: NSABP FC-7, A Phase Ib Study.

PURPOSE: In metastatic colorectal cancer (mCRC), HER2 (ERBB2) gene amplification is implicated in anti-EGFR therapy resistance. We sought to determine the recommended phase II dose (RP2D) and efficacy of neratinib, a pan-ERBB kinase inhibitor, combined with cetuximab, in patients with progressive disease (PD) on anti-EGFR treatment. PATIENTS AND METHODS: Twenty-one patients with quadruple-wild-type, refractory mCRC enrolled in this 3+3 phase Ib study. Standard dosage cetuximab was administered with neratinib at 120 mg, 160 mg, 200 mg, and 240 mg/day orally in 28-day cycles. Samples were collected for molecular and pharmacokinetic studies. RESULTS: Sixteen patients were evaluable for dose-limiting toxicity (DLT). 240 mg was determined to be the RP2D wherein a single DLT occurred (1/7 patients). Treatment-related DLTs were not seen at lower doses. Best response was stable disease (SD) in 7 of 16 (44%) patients. HER2 amplification (chromogenic in situ IHC) was detected in 2 of 21 (9.5%) treatment-naïve tumors and 4 of 16 (25%) biopsies upon trial enrollment (post-anti-EGFR treatment and progression). Compared with matched enrollment biopsies, 6 of 8 (75%) blood samples showed concordance for HER2 CNV in circulating cell-free DNA. Five SD patients had HER2 amplification in either treatment-naïve or enrollment biopsies. Examination of gene-expression, total protein, and protein phosphorylation levels showed relative upregulation of ≥2 members of the HER-family receptors or ligands upon enrollment versus matched treatment-naïve samples. CONCLUSIONS: The RP2D of neratinib in this combination was 240 mg/day, which was well tolerated with low incidence of G3 AEs. There were no objective responses; SD was seen at all neratinib doses. HER2 amplification, detectable in both tissue and blood, was more frequent post-anti-EGFR therapy.

Inpatient prescribing of dual antiplatelet therapy according to the guidelines: a prospective intervention study.

BACKGROUND: In dual antiplatelet therapy (DAPT), low-dose acetylsalicylic acid is combined with a P2Y12 inhibitor. However, combining antithrombotic agents increases the risk of bleeding. Guidelines on DAPT recommend using this combination for a limited period of between three weeks and 30 months. This implies the risk of DAPT being erroneously continued after the intended stop date. OBJECTIVE: The primary objective of this study is to assess the proportion of hospitalized patients treated with DAPT whose treatment deviated erroneously and unintentionally from the guidelines. We also assessed risk factors and the effect of a pharmacist intervention. METHODS: All patients admitted to the Spaarne Gasthuis (Haarlem/ Hoofddorp, the Netherlands) who used DAPT between March 25th, 2019, and June 14th, 2019, were, in addition to receiving regular care, reviewed to assess whether their therapy was in line with the guidelines' recommendation and whether deviations were unintended and erroneous. In the event of an unintended deviation, the pharmacist intervened by contacting the prescriber by phone and giving advice to adjust the antithrombotic therapy in line with the guideline. RESULTS: We included 411 patients, of whom 21 patients (5.1%) had a treatment that deviated from the guidelines. For 11 patients (2.7%), the deviation was unintended and erroneous. The major risk factor for erroneous deviation was the use of DAPT before hospital admission (OR 18.7; 95%CI 4.79-72.7). In patients who used DAPT before admission, 18 out of 58 (31.0%) had a deviation from the guidelines of whom 8 (13.8%) were erroneous. For these eight patients, the pharmacist contacted the prescriber, and in these cases the therapy was adjusted in line with the guidelines. CONCLUSIONS: Adherence to the guidelines recommending DAPT was high within the hospital. However, patients who used DAPT before hospital admission had a higher risk of erroneous prescription of DAPT. Intervention by a pharmacist increased adherence to guidelines and may reduce the number of preventable bleeding cases.

Polyethersulfone based MMMs with 2D materials and ionic liquid for CO2, N2 and CH4 separation.

Increasing concerns on global warming and climate change have led to numerous attempts on developing new membrane materials to reduce excessive CO2 emission into the atmosphere. In the present work, we focused on the separation of CO2 from gas mixtures through two-dimensional (2D) materials based mixed matrix membranes (MMMs). The ionic liquid (IL) 1-Ethyl-3methylimidazolium bis (trifluoromethylsulfonyl) imide together with different weight fractions (0.5-1.5 wt %) 2D materials, such as molybdenum disulfide (MoS2) and hexagonal boron nitride (h-BN), were homogenously blended to prepare polyether sulfone (PES) MMMs. The main aim was to investigate the effect of the addition of 2D materials on the gas separation/permeation properties of the PES membranes. Pure gas permeation for N2, CO2, and CH4 and binary gas mixtures separation for CO2/N2 and CO2/CH4 were investigated through pure PES and modified PES membranes. The prepared membranes were characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and water contact angle tests. The gas permeabilities were found to be improved by average 15-20 times higher compared to pure PES. The [Formula: see text] and [Formula: see text] were improved up to 124% and 18% using PES/h-BN (1 wt %)/IL and PES/MoS2 (1.5 wt %)/IL combination, respectively. In overall, 2D materials and IL together as a filler into PES matrix revealed a significant improvement in the gas separation/permeation properties of PES and can be considered as a competent membrane for CO2/CH4 and CO2/N2 separation.

Cycling and Spatial Navigation in an Enriched, Immersive 3D Virtual Park Environment: A Feasibility Study in Younger and Older Adults.

BACKGROUND: Cognitive decline is a significant public health concern in older adults. Identifying new ways to maintain cognitive and brain health throughout the lifespan is of utmost importance. Simultaneous exercise and cognitive engagement has been shown to enhance brain function in animal and human studies. Virtual reality (VR) may be a promising approach for conducting simultaneous exercise and cognitive studies. In this study, we evaluated the feasibility of cycling in a cognitively enriched and immersive spatial navigation VR environment in younger and older adults. METHODS: A total of 20 younger (25.9 ± 3.7 years) and 20 older (63.6 ± 5.6 years) adults participated in this study. Participants completed four trials (2 learning and 2 recall) of cycling while wearing a head-mounted device (HMD) and navigating a VR park environment. Questionnaires were administered to assess adverse effects, mood, presence, and physical exertion levels associated with cycling in the VR environment. RESULTS: A total of 4 subjects withdrew from the study due to adverse effects, yielding a 90% completion rate. Simulator sickness levels were enhanced in both age groups with exposure to the VR environment but were within an acceptable range. Exposure to the virtual environment was associated with high arousal and low stress levels, suggesting a state of excitement, and most participants reported enjoyment of the spatial navigation task and VR environment. No association was found between physical exertion levels and simulator sickness levels. CONCLUSION: This study demonstrates that spatial navigation while cycling is feasible and that older adults report similar experiences to younger adults. VR may be a powerful tool for engaging physical and cognitive activity in older adults with acceptable adverse effects and with reports of enjoyment. Future studies are needed to assess the efficacy of a combined exercise and cognitive VR program as an intervention for promoting healthy brain aging, especially in older adults with increased risk of age-related cognitive decline.

Assessing test-retest reliability of phase contrast MRI for measuring cerebrospinal fluid and cerebral blood flow dynamics.

PURPOSE: Pathological states occur when cerebrospinal fluid (CSF) and cerebral blood flow (CBF) dynamics become dysregulated in the brain. Phase-contrast MRI (PC-MRI) is a noninvasive imaging technique that enables quantitative measurements of CSF and CBF flow. While studies have validated PC-MRI as an imaging technique for flow, few studies have evaluated its reliability for CSF and CBF flow parameters commonly associated with neurological disease. The purpose of this study was to evaluate test-retest reliability at the cerebral aqueduct (CA) and C2-C3 area using PC-MRI to assess the feasibility of investigating CSF and CBF flow dynamics. METHODS: This study was performed on 27 cognitively normal young adults (ages 20-35 years). Flow data was acquired on a 3T Siemens Prisma using a 2D cine-PC pulse sequence. Three consecutive flow measurements were acquired at the CA and C2-C3 area. Intraclass correlation coefficient (ICC) and coefficient of variance (CV) were used to evaluate intrarater, inter-rater, and test-retest reliability. RESULTS: Among the 26 flow parameters analyzed, 22 had excellent reliability (ICC > 0.80), including measurements of CSF stroke volume, flush peak, and fill peak, and 4 parameters had good reliability (ICC 0.60-0.79). 16 flow parameters had a mean CV ≤ 10%, 7 had a CV ≤ 15%, and 3 had a CV ≤ 30%. All CSF and CBF flow measurements had excellent inter-rater and intrarater reliability (ICC > 0.80). CONCLUSION: This study shows that CSF and CBF flow can be reliably measured at the CA and C2-C3 area using PC-MRI, making it a promising tool for studying flow dynamics in the central nervous system.

A surface gravity traverse on Mars indicates low bedrock density at Gale crater.

Gravimetry, the precise measurement of gravitational fields, can be used to probe the internal structure of Earth and other planets. The Curiosity rover on Mars carries accelerometers normally used for navigation and attitude determination. We have recalibrated them to isolate the signature of the changing gravitational acceleration as the rover climbs through Gale crater. The subsurface rock density is inferred from the measured decrease in gravitational field strength with elevation. The density of the sedimentary rocks in Gale crater is 1680 ± 180 kilograms per cubic meter. This value is lower than expected, indicating a high porosity and constraining maximum burial depths of the rocks over their history.

Customized Cheek Plumper with Friction Lock Attachment for a Completely Edentulous Patient to Enhance Esthetics: A Clinical Report.

Prosthetic rehabilitation of a completely edentulous patient should never be restricted to the replacement of missing teeth. The ultimate aim of complete denture treatment should be restoration of the full range of oral functions and esthetics. Slumped cheeks are always a concern for esthetically demanding complete denture patients. This article describes a simple, scientific, cost-effective technique to improve facial esthetics in a completely edentulous patient with the help of a cheek plumper. The technique used here implements the concept of neutral zone to precisely determine the amount of space available for the cheek plumper. The simple friction lock attachments that retained the cheek plumpers on the prosthesis were also fabricated after determining the space available in the appropriate areas. Thus an effort was made to keep the cheek plumpers unobtrusive yet effective to ensure complete integration of the prosthesis into the stomatognathic system.

The Hollow Maxillary Complete Denture: A Simple, Precise, Single-Flask Technique Using a Caramel Spacer.

The success of removable prostheses ultimately depends on a number of factors such as retention, stability, support, esthetics, and masticatory function. Increased intraoral inter-arch distance leads to an increase in the weight of the prosthesis. This may compromise the retention and resistance, which are key for a successful removable prosthesis. Various methods, techniques, and materials have been reported to minimize the weight of a prosthesis. This article describes a simple, unique, precise single-flask technique for the fabrication of a lightweight maxillary prosthesis using caramel as a 3D spacer, which was "indexed" to obtain a uniform thickness of acrylic around the hollow cavity.

Background levels of methane in Mars' atmosphere show strong seasonal variations.

Variable levels of methane in the martian atmosphere have eluded explanation partly because the measurements are not repeatable in time or location. We report in situ measurements at Gale crater made over a 5-year period by the Tunable Laser Spectrometer on the Curiosity rover. The background levels of methane have a mean value 0.41 ± 0.16 parts per billion by volume (ppbv) (95% confidence interval) and exhibit a strong, repeatable seasonal variation (0.24 to 0.65 ppbv). This variation is greater than that predicted from either ultraviolet degradation of impact-delivered organics on the surface or from the annual surface pressure cycle. The large seasonal variation in the background and occurrences of higher temporary spikes (~7 ppbv) are consistent with small localized sources of methane released from martian surface or subsurface reservoirs.

Clay mineral diversity and abundance in sedimentary rocks of Gale crater, Mars.

Clay minerals provide indicators of the evolution of aqueous conditions and possible habitats for life on ancient Mars. Analyses by the Mars Science Laboratory rover Curiosity show that ~3.5-billion year (Ga) fluvio-lacustrine mudstones in Gale crater contain up to ~28 weight % (wt %) clay minerals. We demonstrate that the species of clay minerals deduced from x-ray diffraction and evolved gas analysis show a strong paleoenvironmental dependency. While perennial lake mudstones are characterized by Fe-saponite, we find that stratigraphic intervals associated with episodic lake drying contain Al-rich, Fe3+-bearing dioctahedral smectite, with minor (3 wt %) quantities of ferripyrophyllite, interpreted as wind-blown detritus, found in candidate aeolian deposits. Our results suggest that dioctahedral smectite formed via near-surface chemical weathering driven by fluctuations in lake level and atmospheric infiltration, a process leading to the redistribution of nutrients and potentially influencing the cycling of gases that help regulate climate.

Variants of latissimus dorsi with a perspective on tendon transfer surgery: an anatomic study.

BACKGROUND: The latissimus dorsi (LD) is often used for tendon transfers to treat massive irreparable posterosuperior rotator cuff tears. The operation requires the LD tendon to be mobilized to reduce tension on the tendon. In that respect, any connection between the LD tendon and contiguous muscles may hamper tendon mobility and affect the surgical outcome. The goal of this study was to document the occurrence of connections between the LD and adjacent muscles and nerves. METHODS: We studied the scapular region on 48 embalmed cadavers. The skin and superficial fascia were removed according to Cunningham's manual of dissection, and the muscle was exposed. RESULTS: It was found that the LD and teres major (TM) muscles are connected by muscle fibers in 10% of the cadavers studied. Another vital discovery was that in some cadavers, the LD tendon was penetrated by a nerve. CONCLUSION: Fascial connections between the LD and TM are well known, but these muscle links are comparatively unusual. From the results of this study, one should pay particular attention to muscle links between the LD and TM during dissection of the LD for transfer. It can also be suggested that during transfer surgery, the LD tendon should be cautiously examined for the possibility of a nerve penetrating it.