Morphological changes and bioaccumulation in response to cadmium exposure in Morchella spongiola, a fungus with potential for detoxification.

Morchella is a genus of edible fungi with strong resistance to cadmium (Cd) and the ability to accumulate it in its mycelia. However, the mechanisms underlying Cd resistance in Morchella remain unknown. In the present study, morphological and physiological responses to Cd were evaluated in the mycelia of Morchella spongiola. Variations in hyphal micromorphology, including twisting, folding, and kinking, in mycelia exposed to different Cd concentrations (0.15, 0.9, 1.5, 2.4, 5.0 mg/L) were observed using scanning electron microscopy. Deposition of Cd precipitates on cell surfaces (at Cd concentrations >2.4 mg/L) was shown by SEM-EDS. Transmission electron microscopy analysis of cells exposed to different concentrations of Cd revealed the loss of intracellular structures and the localization of Cd depositions inside and outside the cell. FTIR analysis showed that functional groups such as C=O, -OH, -NH, and -CH could be responsible for Cd binding on the cell surface of M. spongiola. In addition, intracellular accumulation was observed in cultures at low Cd concentrations (<0.9 mg/L), while extracellular adsorption occurred at higher concentrations. These results provide valuable information on the Cd tolerance mechanism in M. spongiola and provide a robust foundation for further studies on fungal bioremediation strategies.

Neurological assessment of Chinese infants with positional plagiocephaly using a Chinese version of the Infant Neurological International Battery (INFANIB).

PURPOSE: Positional plagiocephaly (PP) is the most common subtype of asymmetric deformity in the infant skull. Cumulative evidence has demonstrated that PP is associated with abnormal neuromotor development; however, neurological assessment scores of infants with PP have not been well established, and PP has not attracted sufficient attention in China. This study used a Chinese version of the Infant Neurological International Battery (INFANIB) to identify neurological abnormalities among infants with PP and to determine the differences between infants with different (mild, moderate, and severe) degrees of PP. METHODS: We compared the neurological evaluation scores between 393 infants with different degrees of PP and 390 healthy infants from 0 to 18 months of age using a Chinese version of the INFANIB. RESULTS: The infants with PP aged 0-7.9 months had lower scores on the spasticity, head and trunk, leg, and French angle subscales and lower total scores than the normal infants. Additionally, the infants with PP aged 9-18 months showed statistically significantly lower scores on the spasticity, head and trunk, vestibular function, leg, and French angle subscales and total scores than the normal infants. Among the PP subgroups, the infants with mild PP had the highest scores, followed by the infants with moderate PP and the infants with severe PP. Compared with the normal infants, the infants with PP had abnormal neurological assessment scores, and the degree of neurological abnormality was associated with the severity of PP. CONCLUSIONS: The INFANIB revealed neurological abnormalities, including asymmetric movements and abnormal muscle tone, postures, and reflexes, in infants with PP, especially those with moderate or severe PP. These abnormalities were similar to those of infants with cerebral palsy. Therefore, PP may serve as a marker of neurodevelopmental risk and should receive considerable attention. Whether moderate or severe PP is related to cerebral palsy remains to be confirmed in long-term follow-up studies and other future studies.

[Relationship between tissular structure and strength of fresh bull periodontal ligament].

OBJECTIVE: To study the relationship between the width and the content of fiber in peridontal ligament (PDL) and the strength of peridontal membrane. METHODS: Fresh mandible of bull was obtained to prepare for a 5 mm x 2 mm x 10 mm cuboid including teeth, peridontal membrane, and alveolar bone. The width of the PDL was measured under a stereomicroseope. Pull stress was loaded on the test piece until it broke. The stress-strain curve was recorded. The broken ends of the PDL was dyed with siriue to adalyze the content of fiber. RESULTS: The relationship between the width of the PDL and the maximum stress was expressed as Y = 9.786e(-3.6693x). The relationship between the width of the PDL and the physiological ultimate stress was expressed as Y = e((2.188(-3.953)x). The relationship between the percentage of fiber and maximum stress was expressed as Y = 20.788-0.755x + 0.007x(2). The relationship between the percentage of fiber and the physiological ultimate stress was expressed as Y = 1.39e(-14) x x(7.666). The initial physiological stress was 0.28 N/mm2. CONCLUSION: The strength of PDL increases with the decrease of PDL width and increase of fiber content.

[A structural mechanics study with human maxillary premolar].

OBJECTIVE: To evaluate the stress distribution and offset of dental and periodontal tissues imposed by changes in inner diameter of pulp cavity. METHODS: Six models of maxillary second bicuspid tooth with different inner diameter of pulp cavity were established, including: (1) calcificated pulp without pulp chamberi (2) mostly calcificated pulp chamber with inward reduction of 0. 5 mm in normal pulp cavity; (3) initially calcificated pulp chamber with inward reduction of 0.25 mm in normal pulp cavity; (4) normal pulp cavity; (5) initially absorbed pulp chamber with outward expansion of 0.25 mm in normal pulp cavity; (6) mostly absorbed pulp chamber with outward expansion of 0.5 mm in normal pulp cavity. Vertical and oblique forces with 160 N were loaded on the central fossa, respectively, in order to calculate the stress distribution of dental and periodontal tissues and the maximum incipient offset of the teeth. RESULTS: With loaded vertical and oblique forces on central fossa, increased stress distribution of periodontal tissues and maximum incipient offset of teeth were found in all of the models, which increased with the increase of pulp cavity. CONCLUSION: The change in inner diameter of pulp cavity has an impact on the stress distribution of periodontal tissues and maximum incipient offset of the second upper bicuspid teeth.