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BACKGROUND: Sport specialization is associated with increased risk of overuse injuries. However, the effects of sport specialization on the risk of overuse injury may differ by specific sport and sociocultural parameters. This study aimed to determine the associations of sport participation and training volume with previous overuse injuries in Japanese male youth soccer players. HYPOTHESIS: Being highly specialized before the age of 12 years and high training volume relative to participant age would be associated with a history of serious overuse injury. STUDY DESIGN: Cross-sectional study. LEVEL OF EVIDENCE: Level 3. METHODS: Survey data were collected from male youth soccer players (seventh-ninth grade) during midseason of the 2020-2021 academic year. Participants completed a questionnaire regarding their status of sport participation (single- and multisport athletes), weekly sports volume in first- sixth grade and injury history in the previous year. Odds ratio (OR) was calculated to identify associations of specialization and training volume with a history of serious overuse injury. RESULTS: A total of 841 players (mean age, 13.7 ± 0.9 years) participated; 11% reported serious overuse injury in the previous year, and 64% participated in other sports before the age of 12 years. Players who participated in other sports at <12 years old (OR, 1.79; 95% CI, 1.09-2.94; P = 0.02) and those who trained for more weekly hours than their age in fifth to sixth grade (OR, 1.70; 95% CI, 1.07-2.72; P = 0.03) had greater odds of reporting serious overuse injuries. CONCLUSION: Multisport athletes and high training volume in fifth-sixth grade were associated with previous serious overuse injuries. CLINICAL RELEVANCE: Coaches and parents of male youth soccer players should be aware of the increased risk of serious overuse injury participating in multiple sports simultaneously, and youth athletes should adhere to age-appropriate volume recommendations.

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A new 3D metal-organic framework (MOF), in which 2D layers are interlaced to form a 3D architecture, was synthesized by a reaction of Cu(BF4)2 and 1,3-bis(4-pyridyl)propane (bpp) in a water/1-hexanol solvent system, and the crystal structure of the MOF was successfully solved. The MOF is reversibly transformed to a 1D chain MOF, which shows gate adsorption properties. The dynamic transformation gives crystal size reduction resulting in a slight change in CO2 adsorption isotherms. The 1D MOF shows selective adsorption/separation properties on benzene and its analogues with similar sizes and shapes (benzene, toluene, and cyclohexane).

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OBJECTIVES: Sleep studies for diagnosing obstructive sleep apnea (OSA) in children are laborious, expensive, inconvenient, and often not readily available. Out-of-center sleep test (OCST) devices have been studied for diagnosing OSA in adults, but few OCST studies have been done in children. The purpose of this study was to clarify the diagnostic reliability of OCST devices for children. METHODS: OCSTs using pulse oximetry and in-laboratory polysomnography (PSG) were performed separately in 686 adults and 119 children. For each apnea-hypopnea index (AHI) measured with PSG, accuracy, sensitivity, specificity, positive/negative likelihood ratio (PLR/NLR), and positive/negative predictive value (PPV/NPV) were calculated for several cutoff values of 3% oxygen desaturation index (ODI) measured with OCST and analyzed. RESULTS: For definitive diagnosis in adults, the specificity, PLR, and PPV with a cutoff value of OCST-ODI 20/h were 98.3%, 29.26, and 97.4%, respectively, to detect PSG-AHI ≥20/h. Corresponding values with a cutoff value of OCST-ODI 15/h were 99%, 46.19, and 99.6% to detect an AHI ≥5/h. For exclusive diagnosis (screening) in adults, sensitivity, NLR, and NPV with a cutoff value of OCST-ODI 5/h were 96.4%, 0.068, and 91.9% to detect PSG-AHI <20/h and 84.1%, 0.21, and 45.9% to detect PSG-AHI <5/h. or definitive diagnosis in children, the corresponding values with a cutoff value of OCST-ODI 25/h were 98.6%, 16.0, and 90.9% to detect PSG-AHI ≥10/h and 98.1%, 8.281, and 90.9% for PSG-AHI ≥5/h. For exclusive diagnosis in children, with a cutoff of OCST-ODI 10/h, the corresponding values were 62.2%, 0.446, and 78.2% to detect PSG-AHI <10/h, 45.3%, 0.674, and 55.1% for PSG-AHI <5/h, and 34.0%, 0.908, and 10.3% for PSG-AHI <1/h. Statistical data of preschool children tended to be worse than those of school age children. CONCLUSIONS: In adults, OCST is reliable for the definitive diagnosis of AHI ≥20/h or ≥5/h and the exclusive diagnosis of AHI <20/h. However, in children, OCST should not be used alone for the definitive diagnosis or exclusive diagnosis.

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Lemierre syndrome (LS) is a rare life-threatening disease that is often caused by an acute oropharyngeal infection with a secondary thrombophlebitis of the internal jugular vein. LS rarely manifests as cranial nerve palsy. To the best of our knowledge, this is the second case report of LS associated with recurrent laryngeal nerve palsy. A 66-year-old female presented to a dental clinic with gingivitis and sore throat. Due to moderate periodontitis, her left first upper molar was extracted. A few days later, she subsequently developed a coarse voice and occipital headaches, and was referred to an otolaryngologist. She was diagnosed with left recurrent laryngeal nerve palsy and subsequent left-sided otitis media, and was referred to us for persistent headaches. She intermittently presented with high-grade fever and complained of salty taste disturbance. Her head magnetic resonance imaging (MRI) revealed left mastoiditis, thrombosis in the left transverse and sigmoid sinus, and left internal jugular vein. Her laboratory tests revealed an elevated white blood cell count, levels of C-reactive protein, and D-dimer. No endogenous coagulopathy was confirmed. Although, blood and cerebrospinal fluid culture grew no microorganisms, respectively, the empirically determined antibiotic therapy was initiated. In a week, the patient defervesced and had no headaches despite persistent thrombosis. Early diagnosis and an immediate antibiotic treatment are crucial for LS patients. Anticoagulation therapy was not needed for our patient and is still controversial for LS.

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CONCLUSIONS: Hydrostatic positive pressure and vasoconstrictor acidified the cochlear fluids, whereas the vasodilator made the fluids alkaline. CBF might play a role in regulating cochlea fluid pH. OBJECTIVES: Cochlea fluid pH is highly dependent on the HCO3(-)/CO2 buffer system. Cochlear blood flow (CBF) supplies O2 and removes CO2. It is speculated that cochlear blood flow changes might affect the balance of the HCO3(-)/CO2 buffer system in the cochlea. It is known that the elevation of inner ear pressure decreases the CBF, and local application of vasodilating or vasoconstricting agents directly to the cochlea changes the CBF. The purpose of this study was to elucidate the effect of positive hydrostatic inner ear pressure and application of a vasodilator and vasoconstrictor of cochlear vessels on the pH of the endolymph and perilymph. METHODS: The authors performed animal physiological experiments on 30 guinea pigs. Hydrostatic positive pressure was infused through a glass capillary tube inserted into the scala tympani of the basal turn. The vasodilator, nitric oxide donor (sodium nitroprusside; SNP), and the vasoconstrictor, bupivacaine, were placed topically onto the round window of the guinea pig cochlea. Endolymph pH (pHe) and endocochlear potential (EP) were monitored by double-barreled ion-selective microelectrodes in the second turn of the guinea pig cochlea. During the topical application study, scala vestibuli perilymph pH (pHv) was also measured simultaneously in the second turn. RESULTS: The application of hydrostatic positive pressure caused a decrease in pHe and EP. Positive perilymphatic pressure caused the endolymph to become acidic pressure-dependently. Application of 3.0% SNP evoked an increase in both the pHe and pHv, following by a gradual recovery to baseline levels. On the other hand, 0.5% bupivacaine caused a decrease in both the pHe and pHv. The EP during topical application showed slight, non-significant changes.

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STUDY OBJECTIVES: Sleep breathing patterns are altered by nasal obstruction and respiratory events. This study aimed to describe the relationships between specific sleep oral flow (OF) patterns, nasal airway obstruction, and respiratory events. METHODS: Nasal flow and OF were measured simultaneously by polysomnography in 85 adults during sleep. OF was measured 2 cm in front of the lips using a pressure sensor. RESULTS: OF could be classified into three patterns: postrespiratory event OF (postevent OF), during-respiratory event OF (during-event OF), and spontaneous arousal-related OF (SpAr-related OF). Postevent OFs begin at the end of airflow reduction, are preceded by respiratory arousal, and are accompanied by postapneic hyperventilation; during-event OFs occur during nasal flow reduction; and SpAr-related OFs to OF begin during stable breathing, and are preceded by spontaneous arousal but are rarely accompanied by apnea/hypopnea. Multivariate regression showed that nasal obstruction was predictive of SpAr-related OF. The relative frequency of SpAr-related OF events was negatively correlated with the apnea-hypopnea index. The fraction of SpAr-related OF duration relative to total OF duration was significantly greater in patients with nasal obstruction than in those without. CONCLUSION: SpAr-related OF was associated with nasal obstruction, but not respiratory events. This pattern thus functions as a "nasal obstruction bypass", mainly in normal subjects and patients with mild sleep disordered breathing (SDB). By contrast, the other two types were related to respiratory events and were typical patterns seen in patients with moderate and severe SDB.

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The crystal structure of Al3O3.5C0.5 (Z = 3) has been characterized by X-ray powder diffraction (XRPD), transmission electron microscopy, and electron probe microanalysis. The title compound is trigonal with space group R3̅m (centrosymmetric) and hexagonal unit-cell dimensions a = 0.29588(1) nm, c = 2.84080(7) nm, and V = 0.21538(1) nm(3). The initial structural model was determined by the charge-flipping method and subsequently refined by the Rietveld method. The final structural model showed the positional disordering of one of the two types of Al sites. The maximum-entropy method-based pattern fitting (MPF) method was used to confirm the validity of the split-atom model, in which conventional structure bias caused by assuming intensity partitioning was minimized. The reliability indices calculated from the MPF were Rwp = 4.03%, S (= Rwp/Re) = 1.17, Rp = 3.08%, RB = 0.82%, and RF = 0.72%. The crystal was composed of antiphase domains, suggesting the occurrence of the high-low phase transition during the cooling process. The transition would be accompanied by the loss of unit-lattice translation, and hence the disordered structural model determined by XRPD might be of the average structure of the low-temperature phase.

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A flexible one-dimensional copper-based coordination polymer (CP) crystal was synthesized and the crystal structure was solved. This CP crystal shows a single step gate adsorption uptake of CO(2) under moderate conditions (268 K ≤ T ≤ 303 K, P < 1 atm) irrespective of no N(2) uptake at 77 K.

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The objective of this study is to develop a device for noninvasive local tissue electrical impedance tomography (EIT) using divided electrodes with guard electrodes and to validate its effectiveness using bioequivalent phantoms. For this purpose, we prepared a measurement device and bioequivalent phantoms, measured the electrical characteristics of the phantoms, and validated the method using the phantoms. Monolayer phantoms mimicking the brain and muscle and bilayer phantoms consisting of muscle and brain layers were prepared. The relative differences between the measured electrical conductivities of the monolayer brain and muscle phantoms and the true values determined by the 4-electrode method were both less than 10%. The relative differences between the measured and true values in the bilayer phantoms were less than 20% in both layers. The biological impedance measurement device that we developed was confirmed to be effective for impedance measurement in bilayer phantoms with different electrical impedances. To develop a device for the early diagnosis of breast diseases, the development of a multi-layer phantom and demonstration of the effectiveness of the device for its examination are necessary. If the device that we developed makes impedance measurement in breast tumors possible, it may be used as a new diagnostic modality for breast diseases.

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