The role of soil structure on the cracking and cadmium leaching behavior of biochar-amended fine-grained soils.

Biochar has shown promising potential for soil remediation, yet its impact on heavy metals (HMs) immobilization often overlooks soil structure, which could influence soil cracking behavior and HMs transport. To address this gap, this study investigates the role of soil structure (dry density and aggregate size) on the cracking and cadmium (Cd) leaching behavior of biochar-amended fine-grained soils. A series of semi-dynamic leaching tests were conducted on samples with and without wetting-drying (W-D) cycles. Based on the proposed improved method for quantifying the effective diffusion coefficient (De) of Cd in unsaturated soils and microstructural analyses, we found that: (1) Higher dry density and larger aggregate generally resulted in smaller De by decreasing soil pore volume. (2) Biochar could connect isolated pores within large aggregates through its internal pores, yielding greater increases in De (294.8%-469.0%) compared to small aggregates (29.1%-77.4%) with 3% biochar. However, further increases in biochar dosage led to decreased De, primarily due to the dense pore structure. (3) Biochar effectively inhibited soil cracking, achieving the highest reduction of 36.8% in surface crack ratio. (4) After W-D cycles, samples exhibited higher De with increasing dry density, with aggravated cracking being the primary cause, suggesting preferential flow within the cracks, particularly those penetrating the soil. This study highlights the importance of careful consideration of soil structure and cracking potential before in situ field application of biochar as a remediation agent for HMs-contaminated fine-grained soils.

Biochar implications for the engineering properties of soils: A review.

Use of biochar as a soil amendment for climate change mitigation and environmental remediation has been intensively studied over the past decade, yet the growing interest in biochar for geo-environmental applications is primarily motivated by its active interactions with soil in terms of engineering properties. The addition of biochar can significantly alter the physical, hydrological, and mechanical properties of soils, but the diverse biochar characteristics and soil properties lead to the fact that a generalized conclusion on the impact of biochar on soil engineering properties is difficult to reach. Considering that the effects of biochar on soil engineering properties could also potentially affect the applications of biochar in other fields, this review intends to provide a comprehensive and critical overview of biochar implications for soil engineering properties. Based on the physicochemical properties of biochar pyrolyzed from varying feedstocks and pyrolysis temperatures, this review analyzed the physical, hydrological, and mechanical performances of biochar-amended soils and the underlying mechanisms. Among others, the analysis releases that the initial state of biochar-amended soil requires special attention when evaluating the effect of biochar on soil engineering properties, yet it is usually neglected in the current studies. The review closes with a brief overview of the potential impacts of engineering properties on other soil processes, and future needs and opportunities for further development of biochar in geo-environmental engineering from academia to practice.

Sudden sensorineural hearing loss (SSHL) following a local anesthetic dental procedure.

Acute sensorineural hearing loss is an uncommon phenomenon in dentistry. We describe the case of a 79-year-old male who presented with acute sensorineural hearing loss occurring 2 days after a tooth extraction procedure under local anesthesia. Possible mechanisms are discussed. He was treated with vasodilators (Ginaton and Alprostadil Injection) and Mecobalamin injection with benefit. High dose oral steroids (1 mg/kg) and low molecular weight dextran were used.

Isolation and evaluation of terrestrial fungi with algicidal ability from Zijin Mountain, Nanjing, China.

Approximately 60 fungal isolates from Zijin Mountain (Nanjing, China) were screened to determine their algicidal ability. The results show that 8 fungi belonging to Ascomycota and 5 belonging to Basidiomycota have algicidal ability. Of these fungi, Irpex lacteus T2b, Trametes hirsuta T24, Trametes versicolor F21a, and Bjerkandera adusta T1 showed strong algicidal ability. The order of fungal chlorophyll-a removal efficiency was as follows: T. versicolor F21a > I. lacteus T2b > B. adusta T1 > T. hirsuta T24. In particular, T. versicolor F21a completely removed algal cells within 30 h, showing the strongest algicidal ability. The results also show that all 4 fungal species degraded algal cells through direct attack. In addition, most of the tested fungi from the order Polyporales of Basidiomycota exhibited strong algicidal activity, suggesting that most fungi that belong to this order have algicidal ability. The findings of this work could direct the search for terrestrial fungi for bloom control.

[Application of electrocochleography and ABR in the diagnosis of auditory neuropathy].

OBJECTIVE: To analyze and compare the clinical application of alternating click evoked electrocochleography (ECochG) and auditory brainstem response (ABR) in the diagnosis of auditory neuropathy (AN) subjects. METHOD: ECochGs and ABRs were recorded in 16 patients (32 ears) with AN/AD as AN group and 20 patients (26 ears) with sensorineural hearing loss(SNHL) as control group. Test stimuli were alternating polarity clicks. (1) To compare the occurrence rate of ECochGs and ABRs in AN patients. (2) To compare the peak latency of CAPs, absolute amplitude of CAPs, and amplitude ratios of -SP and CAP between AN group and control group. RESULT: ECochGs (--SPs or CAPs) presented in 78.1% (25 among 32 ears) of AN patients. CAPs latency of AN group was shorter than control group (P < 0.05), CAP absolute amplitude of AN group was lower than normal group (P < 0.05), while --SP/CAP was higher than control group (P < 0.01). Deformed ABRs presented in only 5 ears among 32 tested AN ears, while relative good ABR waveforms were evoked in control group. The occurrence rate of ABRs (15.6%) was significantly lower than that of ECochGs in AN patients (P < 0.01). CONCLUSION: Both ECochGs and ABRs play important role in the diagnosis of AN. The capacity of temporal processing is significantly impaired while the intensity perception related capability is intact in AN patients.

[Clinical analysis of 430 cases of skull base lesions].

OBJECTIVE: Through analysis of surgical treatment and repair methods for the skull base lesions, to summarize the type, sites, characters of the lesions and the methods of surgical treatment and repair, and to provide the beneficial experience for the surgeons. METHODS: Four hundred and thirty patients were hospitalized and treated surgically between Feb. 1982 and Dec, 2002, and their clinical data were analyzed. RESULTS: Of 430 patients, 265 (61.6%) were male, 165 (38.4%) female. The mean age was 36. 1 years old (range from 2.5 to 76.0). In 173 cases (40.2%), the lesions were on the left side of the skull base, 178 cases (41.4%) on the right, 79 cases (18.4%) involving the central and both side of the skull base. In 116 cases (27.0%), the lesions were located in anterior skull base, 57 (13.3%) in central, 174 (40.5%) in lateral and posterior, and the remainder 83 cases (19.5%) in two or more regions. Of 430 cases, 283 (65.8%) were tumors, among them, 154 (35.8%) were benign, 129 (30.0%) malignant, 76 (17.7%) trauma, 42 (9.8%) congenital, 18 (4.2%) infection, 11 (2.6%) unknown. All patients were surgically treated. Of them, 43 cases were treated for 2 times, 5 cases for 3 times, 4 for 4 times, 1 for 5 times, 3 for 6 times. The total were 514 times. The bone defect was reconstructed in 95 cases (22.1%). The dura mater was repaired in 117 cases (27.2%). The postoperative complications occurred in 27 cases. Two cases died in 2 and 3 days after operation because of brain hernia with the ligation of common carotid artery and internal carotid artery for artery rupture. No death occurred during operation. CONCLUSIONS: The majority of the skull base lesions were tumors. The male patients were more than female. Appropriate surgical approach and better perioperative treatment could harvest the satisfactory effect.