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Shunqing Su,1 Xiumei Ding,1 Huijuan Zou,1 Yuechun Lin,1 Jianmin Huang,1 Disheng Xiong,1 Jinan Kuan,1 Yanhong Zhang,2 Rurong Xie2 1Department of Burn&Plast, Dalang Hospital of Dongguan, Dongguang, Guangdong, 523780, People’s Republic of China; 2Department of Wound Repair, Hongmei Hospital of Dongguan, Dongguang, Guangdong, 523160, People’s Republic of ChinaCorrespondence: Xiumei DingDepartment of Burn&Plast, Dalang Hospital of Dongguan, No. 85 of Jinlangzhong Street, Dalang District, Dongguang, 523780, People’s Republic of ChinaTel +86 769-83009512Fax +86 769-83033122Email ding_xm123@outlook.comObjective: The present study aims to explore the individualized treatment options for multisite pressure ulcer (PU) at various stages in elderly patients with multiple medical conditions.Methods: Stages 1 and 2 PU at 146 sites were treated with closed negative pressure suction combined with continuous micro-oxygen perfusion and the local application of foam dressings, silver ion dressings, and moist burn cream. Stages 3 and 4 PU in the sacrococcygeal region were treated with skin or myocutaneous flap transplantation.Results: Stages 1 and 2 PU healed after treatment with closed negative pressure suction combined with continuous micro-oxygen perfusion and dressing changes. One case died during hospitalization due to an illness. Skin or myocutaneous flap repair was conducted in 34 cases of stage 3 or 4 PU in the sacrococcygeal area. Of these cases, 28 achieved primary healing, and 6 required two or three surgeries, 5 of which received micro-skin implantation. In addition, 10 small deep PU at other sites were repaired by direct excision and suturing or local flap repair. Seven cases were transferred to other departments or hospitals due to concomitant diseases or were discharged automatically without surgical treatment.Conclusion: Home care for geriatric patients is difficult. PU often occur at multiple sites because of the duration of various pressures, and differen

Oxygenic photosynthesis fundamentally transformed all major biogeochemical cycles and increased the size and complexity of Earth's biosphere. However, there is still debate about when this metabolism evolved. As oxygenic photosynthesis is the only significant source of O-2 at Earth's surface, O-2 -sensitive trace element enrichments and isotopic signatures in Archean sedimentary rocks can potentially be used to determine the onset of oxygenic photosynthesis by tracking shifts in the oxidative capacity of Earth's surface environment. Here, we present an extensive new Archean U isotope record from iron formations, organic-rich shales, and paleosols. Variability in delta U-238 values gradually increased from Archean to Phanerozoic, consistent with current view of gradual oxidation of Earth's surface. In addition, statistical analysis on available delta U-238 data indicates a turning point of delta U-238 variability at roughly 3.0 billon years ago. We suggest that such a turning point in delta U-238 variability indicates the initiation of relatively large-scale oxidative weathering of U(IV)-bearing minerals, implying that oxygenic photosynthesis may have evolved before 3.0 billion years ago.

Oxygenic photosynthesis fundamentally transformed all major biogeochemical cycles and increased the size and complexity of Earth's biosphere. However, there is still debate about when this metabolism evolved. As oxygenic photosynthesis is the only significant source of O-2 at Earth's surface, O-2 -sensitive trace element enrichments and isotopic signatures in Archean sedimentary rocks can potentially be used to determine the onset of oxygenic photosynthesis by tracking shifts in the oxidative capacity of Earth's surface environment. Here, we present an extensive new Archean U isotope record from iron formations, organic-rich shales, and paleosols. Variability in delta U-238 values gradually increased from Archean to Phanerozoic, consistent with current view of gradual oxidation of Earth's surface. In addition, statistical analysis on available delta U-238 data indicates a turning point of delta U-238 variability at roughly 3.0 billon years ago. We suggest that such a turning point in delta U-238 variability indicates the initiation of relatively large-scale oxidative weathering of U(IV)-bearing minerals, implying that oxygenic photosynthesis may have evolved before 3.0 billion years ago.

Oxygenic photosynthesis fundamentally transformed all major biogeochemical cycles and increased the size and complexity of Earth's biosphere. However, there is still debate about when this metabolism evolved. As oxygenic photosynthesis is the only significant source of O-2 at Earth's surface, O-2 -sensitive trace element enrichments and isotopic signatures in Archean sedimentary rocks can potentially be used to determine the onset of oxygenic photosynthesis by tracking shifts in the oxidative capacity of Earth's surface environment. Here, we present an extensive new Archean U isotope record from iron formations, organic-rich shales, and paleosols. Variability in delta U-238 values gradually increased from Archean to Phanerozoic, consistent with current view of gradual oxidation of Earth's surface. In addition, statistical analysis on available delta U-238 data indicates a turning point of delta U-238 variability at roughly 3.0 billon years ago. We suggest that such a turning point in delta U-238 variability indicates the initiation of relatively large-scale oxidative weathering of U(IV)-bearing minerals, implying that oxygenic photosynthesis may have evolved before 3.0 billion years ago.