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1.
Am J Bot ; 111(3): e16290, 2024 03.
Artículo en Inglés | MEDLINE | ID: mdl-38380953

RESUMEN

PREMISE: Stem xylem transports water and nutrients, mechanically supports aboveground tissues, and stores water and nonstructural carbohydrates. These three functions are associated with three types of cells-vessel, fiber, and parenchyma, respectively. METHODS: We measured stem theoretical hydraulic conductivity (Kt), modulus of elasticity (MOE), tissue water content, starch, soluble sugars, cellulose, and xylem anatomical traits in 15 liana and 16 tree species across three contrasting sites in Southwest China. RESULTS: Lianas had higher hydraulic efficiency and tissue water content, but lower MOE and cellulose than trees. Storage traits (starch and soluble sugars) did not significantly differ between lianas and trees, and trait variation was explained mainly by site, highlighting how environment shapes plant storage strategies. Kt was significantly positively correlated with vessel diameter and vessel area fraction in lianas and all species combined. The MOE was significantly positively correlated with fiber area fraction, wood density, and cellulose in lianas and across all species. The tissue water content was significantly associated with parenchyma area fraction in lianas. Support function was strongly linked with transport and storage functions in lianas. In trees, transport and support functions were not correlated, while storage function was tightly linked with transport and support functions. CONCLUSIONS: These findings enhance our understanding of the relationship between stem xylem structure and function in lianas and trees, providing valuable insights into how plants adapt to environmental changes and the distinct ecological strategies employed by lianas and by trees to balance the demands of hydraulic transport, mechanical support, and storage.


Asunto(s)
Árboles , Xilema , Fenómenos Biomecánicos , Agua , Celulosa , Almidón , Azúcares
2.
Am J Case Rep ; 25: e944371, 2024 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-38902917

RESUMEN

BACKGROUND Fetus in fetu (FIF), or parasitic fetus, is a rare malformation that typically occurs in the retroperitoneum, but can be found in other unusual locations, such as the skull, sacrum, and mouth. The presence of a spine is necessary for diagnosis. CASE REPORT Intracranial FIFs were retrospectively studied. Abnormalities were detected in the fetal head during a 33-week prenatal examination; however, MRI could not provide more information, due to space occupation. A baby girl was born via cesarean delivery at 37 weeks, with a large head circumference. She had delays in motor skills and speech development, only able to say "mom". There was a large mass in the cerebral hemisphere, with a 13-cm maximum diameter, smooth boundary, and internal bone structure visible on head CT scan. Both ventricles and third ventricle had hydrops, with a fetal shape at a continuous level, along with apparent compression near the cerebral parenchyma. After performing preoperative examinations, laboratory tests, and surgical planning, craniotomy was performed on the FIF, under general anesthesia. Following complete mass resection, mouth, eye, arm, and hand shapes could be observed. The patient was unconscious after surgery and had seizures that were difficult to control. She died 12 days after surgery. Teratomas can be distinguished based on anatomy and imaging. Surgical resection is the only curative treatment and its prognosis is poor. CONCLUSIONS Intracranial FIF cases are rare and require early diagnosis and surgical treatment. Differentiating between FIF and teratoma is crucial, and monitoring alpha-fetoprotein levels after surgery can help detect recurrence.


Asunto(s)
Teratoma , Humanos , Femenino , Recién Nacido , Pronóstico , Teratoma/cirugía , Teratoma/diagnóstico por imagen , Teratoma/diagnóstico , Embarazo , Feto/cirugía , Neoplasias Encefálicas/cirugía , Neoplasias Encefálicas/diagnóstico por imagen , Resultado Fatal , Craneotomía , Imagen por Resonancia Magnética , Adulto , Tomografía Computarizada por Rayos X
3.
Bioresour Technol ; 397: 130460, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38373505

RESUMEN

A novel efficient pretreatment system containing alkaline deep eutectic solvent (DES) and tetrahydrofuran (THF) was developed in the present study. Under pretreatment conditions of 160 ℃ and 1 h, DES-THF pretreatment was more efficient (81.61%) in cellulose digestibility improvement than DES (choline chloride/monoethanolamine, 67.54%). To further explore lignin structural transformation and lignin-cellulase interaction after pretreatment, milled wood lignin (MWL) was extracted and characterized. Compared with DES-MWL, DES-THF-MWL showed an increased carboxyl group content (24.0%) and decreased condensed phenolic hydroxyl content (9.1%). In DES-MWL, ß-O-4 content was 21.79%, while in DES-THF-MWL, ß-O-4 accounted for 45.45%, indicating that the addition of THF alleviated cleavage of ß-O-4 alkyl ether bonds. Fluorescence emission spectroscopy results showed that quenching mechanism of DES-THF-MWL and cellulase was dynamic, which was different from other lignin. Compared with DES-MWL, decreased Ka between DES-THF-MWL and cellulase indicated decreasing interaction between them. DES-THF pretreatment provides a novel pretreatment method for bioenergy.


Asunto(s)
Celulasa , Lignina , Lignina/química , Triticum , Disolventes Eutécticos Profundos , Solventes/química , Hidrólisis , Biomasa
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