[Enlightening from optimizing post-authorization safety monitoring system of SARS-CoV-2 vaccines in major economies worldwide]

Ongoing global pandemic of Coronavirus Disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has promoted the unprecedented rapid development and large-scale rolling out of different platform-based COVID-19 vaccines worldwide. How to effectively respond to the expected scale increasing adverse events after vaccination campaign of COVID-19 vaccines is a common problem faced by the world. A lot of countries and regions around the world have arranged in advance at different levels, optimizing the original vaccine safety monitoring system from the perspectives of strengthening the foundation and capabilities, promoting internal and external cooperation, upgrading methods, as well as improving transparency and public communication, which has ensured the good and efficient operation of the system and can provide reference for the construction of relevant fields in China.

Assessment of iris volume in glaucoma patients with type 2 diabetes mellitus by AS-OCT

AIM

To examine the change of iris volume measured by CASIA2 anterior segment optical coherence tomography (AS-OCT) in glaucoma patients with or without type 2 diabetes mellitus (T2DM) and explore if there is a correlation between hemoglobin A1c (HbA1c) level and iris volume.

METHODS

In a cross-sectional study, 72 patients (115 eyes) were divided into two groups: primary open angle glaucoma (POAG) group (55 eyes) and primary angle-closure glaucoma (PACG) group (60 eyes). Patients in each group were separately classified into patients with or without T2DM. Iris volume and glycosylated HbA1c level were measured and analyzed.

RESULTS

In the PACG group, diabetic patients' iris volume was significantly lower than those of non-diabetics (P=0.02), and there was a significant correlation between iris volume and HbA1c level in the PACG group (r=-0.26, P=0.04). However, diabetic POAG patients' iris volume was noticeably higher than those of non-diabetics (P=0.01), and there was a significant correlation between HbA1c level and iris volume (r=0.32, P=0.02).

CONCLUSION

Diabetes mellitus impact iris volume size, as seen by increased iris volume in the POAG group and decreased iris volume in the PACG group. In addition, iris volume is significantly correlated with HbA1c level in glaucoma patients. These findings imply that T2DM may compromise iris ultrastructure in glaucoma patients.

[The surveillance analysis of the adverse events following immunization of the domestic 13-valent pneumococcal polysaccharide conjugate vaccine in Zhejiang Province]

To evaluate the safety of the domestic 13-valent pneumococcal polysaccharide conjugate vaccine-tetanus toxoid protein (PCV13-TT) after its licensure. The adverse event following immunization (AEFI) and the vaccination data of PCV13-TT in Zhejiang province from July 2020 to October 2021 were collected from national adverse event following immunization surveillance system and Zhejiang provincial immunization information system. Descriptive epidemiological method was used for this analysis. From July 2020 to October 2021, 302 317 doses of PCV13-TT were administered in children under 6 years old in Zhejiang Province and 636 AEFI case reports were received, with a reporting rate of 21.04 per 10 000 doses. Of these AEFI cases, 97.17% were mild vaccine product-related reaction (20.54 per 10 000 doses) and 95.44% occurred in the 0-1 d after vaccination (20.08 per 10 000 doses). The most common clinical diagnoses of AEFI included fever (224 cases), redness (204 cases), and induration (190 cases), while allergic rash (11 cases) was the most common diagnosis among the abnormal reactions. In conclusion,the present results bolstered that the domestic PCV13-TT was generally well tolerated in children under 6 years old in Zhejiang Province.

Association of macular corneal dystrophy with excessive cell senescence and apoptosis induced by the novel mutant CHST6

Macular corneal dystrophy (MCD) is a rare form of hereditary corneal dystrophy caused by CHST6 mutations. Owing to the genetic heterogeneity and population differences among patients with MCD, the genetic cause of MCD has not been fully elucidated, and the pathogenesis underlying the genetic mutation is still unclear. In this study, Chinese families and sporadic patients were included as subjects, and clinical and genetic analyses were performed to detect novel CHST6 mutations. In addition, the underlying pathogenic mechanisms of MCD were investigated by in vitro cell experiments. Two consanguineously married families and 10 sporadic patients with MCD were enrolled. Direct sequencing of the CHST6 gene was performed in all the patients to identify novel mutations. Wild-type and mutant overexpression cell lines were constructed to study the effects of the mutation in vitro. The expressions of endoplasmic reticulum (ER) stress markers and apoptotic factors, cell senescence, and migration levels tests were performed in different overexpression cell lines. As a result, four novel mutations (R155Afs*66, S84Cfs*17, E71G, and E71Q) and 10 previously reported mutations in the CHST6 gene were identified. Among the reported mutations, the most frequent mutations detected in the patients were L21Rfs*88 (4/14) and L21H (4/14). All the novel mutations were absent in the 50 healthy controls and were predicted to alter highly conserved amino acids across the different species and considered to be "disease causing" by function prediction. The results of the in vitro cell experiment further demonstrated that the novel homozygous frameshift mutations (S84Cfs*17 and R155Afs*66) of CHST6 detected in the consanguineously married families could lead to truncated proteins with defect functions, higher ER stress and apoptotic levels, decreased cell migration, and excessive cell senescence in corneal stromal cells, thereby affecting the normal functions of corneal stromal cells. These changes might play important roles in corneal opacity, which is characteristic of corneas with MCD. Our study extended the existing spectrum of disease-causing mutations and further elucidated the underlying pathogenic mechanisms of MCD.

[A case of subacute combined degeneration of spinal cord caused by inhaling laughing gas]

Laughing gas (Nitrogen monoxide) is currently abused due to its low price and easy availability. This article discussed the clinical manifestations of a patient with subacute combined degeneration of the spinal cord caused by inhalation of laughing gas. The patient developed numbness of extremities, unstable walking, and decreased serum vitamin B(12) level. MRI of the cervical spine showed abnormal signals in the lateral and posterior cords of the cervical spinal cord (C2-6) , neuroelectrophysiological examination showed peripheral nerve damage in the extremities. After treatment with vitamin B(12) supplementation, the patient's condition gradually improved. Clinicians diagnose subacute combined degeneration of the spinal cord, especially when the patient has no gastrointestinal disease, diet, malnutrition, etc., they need to carefully inquire about the history of nitrous oxide inhalation to avoid missed diagnosis.

Mesoporous cellulose-chitosan composite hydrogel fabricated via the co-dissolution-regeneration process as biosorbent of heavy metals

Developing low-cost and high-performance biosorbent for water purification continues drawing more and more attention. In this study, cellulose-chitosan composite hydrogels were fabricated via a co-dissolution and regeneration process using a molten salt hydrate (a 60 wt% aqueous solution of LiBr) as a solvent. The addition of chitosan not only introduced functionality for metal adsorption but also increased the specific surface area and improved the mechanical strength of the composite hydrogel, compared to pure cellulose hydrogel. Batch adsorption experiments indicated that the composite hydrogel with 37% cellulose and 63% chitosan exhibited an adsorption capacity of 94.3 mg/g (1.49 mmol/g) toward Cu²⁺ at 23 °C, pH 5, and initial metal concentration of 1500 mg/L, which was 10 times greater than the adsorption capacity of pure cellulose hydrogel. Competitive adsorption from a mixed metals solution revealed that the cellulose-chitosan composite hydrogel exhibited selective adsorption of the metals in the order of Cu²⁺ > Zn²⁺ > Co²⁺. This study successfully demonstrated an innovative method to fabricate biosorbents from abundant and renewable natural polymers (cellulose and chitosan) for removing metal ions from water.

[An exploratory framework of vaccine hesitancy monitoring and early warning system in China]

Vaccine hesitancy has spread worldwide recent years and resulting in increasing incidence of some well-controlled vaccine-preventable diseases, which is extremely unfavorable to the consolidation of the national immunization programme and the elimination of corresponding diseases. Based on the Complacency, Convenience and Confidence ("3Cs") model of vaccine hesitancy, combined with the practice experience of management of quality control through the whole vaccine life cycle in China, we introduce a framework of vaccine hesitancy monitoring and early warning in China to provide a reference for carrying out corresponding work. The indicator system of the framework derives from monitoring of vaccine life cycle quality management, population vaccine confidence, and service availability.

Associations of lens thickness and axial length with outcomes of laser peripheral iridotomy

AIM

To investigate the association of axial length (AL), lens thickness (LT), and lens vault (LV) with postoperative anterior chamber angle metrics after laser peripheral iridotomy (LPI).

METHODS

Prospective observational study of 69 patients (97 eyes) were diagnosed as primary angle-closure suspect (PACS), primary angle closure (PAC) or primary angle-closure glaucoma (PACG). AL, LT, anterior central chamber depth (ACD), angle opening distance (AOD), trabecular iris angle (TIA), and angle recess area (ARA) were measured before and 1wk after LPI. The association between AL, LT, LV with ACD, AOD, TIA, ARA were analyzed by comparing the differences between preoperative and postoperative measurements for anterior segment biometric parameters.

RESULTS

ACD, AOD, TIA, and ARA were significantly increased after LPI (all P<0.05). Greater LT was significantly associated with greater postoperative increases in ACD, AOD, TIA, and ARA (all P<0.05). AL was not significantly associated with changes of anterior segment biometric parameters. Greater LV was significantly associated with greater postoperative increases in ACD, AOD, and TIA (all P<0.05), but was not significantly associated with changes of ARA.

CONCLUSION

Greater baseline LT and LV measurements are associated with greater increases in anterior segment biometric parameters after laser peripheral iridotomy. AL are not associated with the change of anterior segment biometric parameters.

Mutation analysis of FBN1 gene in two Chinese families with congenital ectopia lentis in northern China

AIM

To summarize the phenotypes and identify the underlying genetic cause of the fibrillin-1 (FBN1) gene responsible for congenital ectopia lentis (EL) in two Chinese families in northern China.

METHODS

A detailed family history and clinical data from all participants were collected by clinical examination. The candidate genes were captured and sequenced by targeted next-generation sequencing, and the results were confirmed by Sanger sequencing. Haplotyping was used to confirm the mutation sequence. Real-time PCR was used to determine the FBN1 messenger ribonucleic acid (mRNA) levels in patients with EL and in unaffected family members.

RESULTS

The probands and other patients in the two families were affected with congenital isolated EL. A heterozygous FBN1 mutation in exon 21 (c.2420_IVS20-8 delTCTGAAACAinsCGAAAG) was identified in FAMILY-1. A heterozygous FBN1 mutation in exon 14 (c.1633C>T, p.R545C) was identified in FAMILY-2. Each mutation co-segregated with the affected individuals in the family and did not exist in unaffected family members and 200 unrelated normal controls.

CONCLUSION

The insertion-deletion mutation (c.2420 IVS20-8delTCTGAAACA insCGAAAG) in the FBN1 gene is first identified in isolated EL. The mutation (c.1633C>T) in the FBN1 gene was a known mutation in EL patient. The variable phenotypes among the patients expand the phenotypic spectrum of EL in a different ethnic background.

[Post-marketing observation on safety of inactivated enterovirus A71 vaccine (human diploid cell)]

Objective: To evaluate the post-marketing safety of inactivated Enterovirus type 71 (EV-A71) vaccine (human diploid cell) . Methods: A total of 20 191 healthy children aged 6 to 59 months were invited to receive 2 doses of EV-A71 vaccine in Zhejiang Province from September 2016 to December 2017. Child caregivers were followed up on the 4(th) or 5(th) day after each EV-A71 vaccination, and the incidence of local, systemic, and other adverse events within 3 days after vaccination was recorded to assess vaccine safety. Describe the differences in adverse events among children with different characteristics. Results: A total of 32 230 doses were observed in this study, of which 20 191 and 12 039 were vaccinated for the first and the second dose, respectively; and the incidence of adverse events within 3 days was 2.045% (413 doses) and 1.611% (194 doses), respectively. After the first and the second dose, the number of systemic adverse events was the highest, 371 and 175 cases, respectively, with an incidence of 1.837% and 1.454%, respectively; the number of local adverse events was the lowest, 14 and 2 doses, respectively, with an incidence of 0.069% and 0.017%. Local adverse events occurred after vaccination were generally mild, and only 2 patients had level of 3; among the systemic adverse events, 39 patients had a fever level of 3 or higher, accounting for 8.2% of the total fever. Most of the symptoms in the local adverse events did not require treatment, only 3 cases of vaccination site rash and 2 cases of pruritus were self-purchased drugs or outpatient treatment; except for 5 cases of fever, the other symptoms were not hospitalized in the case of systemic adverse events. Conclusion: The incidence of adverse events within 3 days after vaccination with EV-A71 vaccine was low in children, mainly systemic adverse events, and the prognosis was good.

[Post-marketing safety analysis of inactivated enterovirus A71 vaccines]

Objectives: To evaluate the safety of inactivated enterovirus A71(EV-A71) vaccines after large-scale immunization in the community. Methods: We selected EV-A71 susceptible people (healthy children) aged 6-59 months in vaccination clinics from 89 counties in Zhejiang Province between April 2016 and March 2018. All local and systematic adverse actions were collected by 30 min on-site inspection, within 3 days and 4-30 days follow-up. Chi-square test and Fisher's exact test were used to compare the difference of AEs incidence in various characteristics among two groups. Results: A total of 71 663 doses of vaccines were included for active safety analysis, which included 37 331 doses in boys and 34 332 doses in girls. Among all the doses, children aged 6 to 11 months, 12 to 23 months and 24 to 59 months were received 13 707, 32 639 and 25 317 doses respectively. The incidence of adverse reactions within 30 min, 3 days and 4-30 days were 0.33% (239 doses), 1.58% (1 133 doses) and 0.34% (244 doses) respectively. Adverse reactions within 3 days were 1 372 doses, with a incidence of 1.91%; among all the cases, 539 doses (0.75%) were grade 1, 677 doses (0.94%) were grade 2 and 156 doses (0.22%) were grade 3, no grade-4 adverse reaction was reported. The common local adverse reactions were redness, swelling and pruritus, with the incidence rates were 0.05% (39 doses), 0.02% (16 doses) and 0.02% (12 doses), respectively, while the most common systemic adverse reaction was pyrexia with an incidence of 1.19% (856 doses), followed by diarrhea and anorexia with the incidence rates were 0.15% (104 doses) and 0.13% (90 doses) respectively. Conclusion: Most adverse actions of EV-A71 vaccines were mild and moderate and majority of them were common adverse actions. No new adverse reactions were found in the study.

Novel mutations in CRYBB1/CRYBB2 identified by targeted exome sequencing in Chinese families with congenital cataract

AIM

To summarize the phenotypes and identify the underlying genetic cause of the CRYBB1 and CRYBB2 gene responsible for congenital cataract in two Chinese families.

METHODS

Detailed family histories and clinical data were collected from patients during an ophthalmologic examination. Of 523 inheritable genetic vision system-related genes were captured and sequenced by targeted next-generation sequencing, and the results were confirmed by Sanger sequencing. The possible functional impacts of an amino acid substitution were performed with PolyPhen-2 and SIFT predictions.

RESULTS

The patients in the two families were affected with congenital cataract. Sixty-five (FAMILY-1) and sixty-two (FAMILY-2) single-nucleotide polymorphisms and indels were selected by recommended filtering criteria. Segregation was then analyzed by applying Sanger sequencing with the family members. A heterozygous CRYBB1 mutation in exon 4 (c.347T>C, p.L116P) was identified in sixteen patients in FAMILY-1. A heterozygous CRYBB2 mutation in exon 5 (c.355G>A, p.G119R) was identified in three patients in FAMILY-2. Each mutation co-segregated with the affected individuals and did not exist in unaffected family members and 200 unrelated normal controls. The mutation was predicted to be highly conservative and to be deleterious by both PolyPhen-2 and SIFT.

CONCLUSION

The CRYBB1 mutation (c.347T>C) and CRYBB2 mutation (c.355G>A) are novel in patients with congenital cataract. We summarize the variable phenotypes among the patients, which expanded the phenotypic spectrum of congenital cataract in a different ethnic background.

Corneal infection in Shandong peninsula of China: a 10-year retrospective study on 578 cases

AIM

To determine the epidemiological characteristics, clinical signs, laboratory findings, and outcomes in patients with corneal infection in Shandong peninsula of China.

METHODS

The medical records of 578 inpatients (578 eyes) with corneal infection were reviewed retrospectively for demographic characteristics, risk factors, seasonal variation, clinical signs, laboratory findings, and treatment strategy. Patient history, ocular examination findings using slit-lamp biomicroscopy, laboratory findings resulted from microbiological cultures, and treatment.

RESULTS

Fungal keratitis constituted 58.48% of cases of infectious keratitis among the inpatients, followed by herpes simplex keratitis (20.76%), bacterial keratitis (19.03%) and acanthamoeba keratitis (1.73%). The most common risk factor was corneal trauma (71.80%). The direct microscopic examination (338 cases) using potassium hydroxide (KOH) wet mounts was positive in 296 cases (87.57%). Among the 298 fungal culture-positive cases, Fusarium species were the most common isolates (70.47%). A total of 517 cases (89.45%) received surgical intervention, including 255 (44.12%) cases of penetrating keratoplasty, 74 (12.80%) cases of lamellar keratoplasty which has become increasingly popular, and 77 cases (13.32%) of evisceration or enucleation.

CONCLUSION

At present, infectious keratitis is a primary corneal disease causing blindness in China. With Fusarium species being the most commonly identified pathogens, fungal keratitis is the leading cause of severe infectious corneal ulcers in Shandong peninsula of China.

A novel method to derive and expand mice neural stem cells efficiently without neuro-sphere formation

Neural stem cells (NSCs) are multi-potent stem cells able to self-renew and generate immature and differentiated cell populations by asymmetric division. The NSCs are of considerable interest for cell replacement in neuro-degenerative diseases. NSCs are usually identified and expanded by their ability to generate free-floating aggregates termed neurospheres. However, neurospheres are not a pure population of NSCs with as little as 1% population in primary spheres. Neurospheres also contain neurons, astrocytes and oligodendrocytes. The heterogeneity of these cells may hinder their repopulation potential when used in cell transplantation. Furthermore, to obtain 1 million NSCs by the neurosphere protocol usually takes one month, which is inconvenient for future clinical trials. In this study, we tried to derive the NSCs from mice embryo neuroepithelium without neurosphere formation. Three different protocols were compared. We generated a direct and efficient NSCs generation, expanding and freezing protocol. This protocol can provide sufficient amount of the NSCs from first a few passages for cell transplantation.

Sulfite (SPORL) pretreatment of switchgrass for enzymatic saccharification

SPORL (Sulfite Pretreatment to Overcome Recalcitrance of Lignocellulose) pretreatment was applied to switchgrass and optimized through an experimental design using Response Surface Methodology within the range of temperature (163-197 °C), time (3-37 min), sulfuric acid dosage (0.8-4.2% on switchgrass), and sodium sulfite dosage (0.6-7.4% on switchgrass). Performance of SPORL was compared with that of dilute acid (DA) and alkali (AL) in switchgrass pretreatment. Results indicated that SPORL pretreatment improved the digestibility of switchgrass through sufficiently removing hemicellulose, partially dissolving lignin, and reducing hydrophobicity of lignin by sulfonation. The removal of hemicellulose was more critical to substrate digestibility than the removal of lignin during SPORL pretreatment. SPORL pretreated switchgrass had better enzymatic digestibility than DA and AL pretreated ones. The SPORL pretreated switchgrass could be hydrolyzed by 83% within 48 h with 15 FPU (filter paper unit) cellulase and 30 CBU (cellobiose unit) β-glucosidase/g cellulose.

Monocytic differentiation of K562 cells induced by proanthocyanidins from grape seeds

Grape seeds procyanidins can inhibit the proliferation of some cancer cell lines and have strong antioxidant activity. The purpose of this study was to investigate whether grape seeds procyanidins affect the proliferation and redifferentiation in K562 cells. The sulforhodamine B colorimetric assay and trypan blue staining were used to measure cell proliferation and survival. Morphological changes, NBT reductive activity, and surface antigens were used to detect redifferentiation of K562 cells. Intracellular reactive oxygen species (iROS) were detected by a fluorescent probe. Grape seeds procyanidins inhibited cell proliferation but the treatment did not appreciably increase lethality. After treatment with grape seeds procyanidins, a typical differentiated morphology was observed. The positive rate of CD11b and CD14 cells and NBT reductive activities increased significantly. As antioxidants, grape seeds procyanidins can induce arrest in the phase G1 and decrease iROS formation. All results indicate that the antioxidant grape seeds procyanidins are likely to induce monocytic differentiation in leukemia cells, mostly through decreasing iROS formation and inducing phase G1 arrest.

Comparisons of SPORL and dilute acid pretreatments for sugar and ethanol productions from aspen

This study reports comparative evaluations of sugar and ethanol production from a native aspen (Populus tremuloides) between sulfite pretreatment to overcome recalcitrance of lignocellulose (SPORL) and dilute acid (DA) pretreatments. All aqueous pretreatments were carried out in a laboratory wood pulping digester using wood chips at 170°C with a liquid to oven dry (od) wood ratio (L/W) of 3:1 at two levels of acid charge on wood of 0.56 and 1.11%. Sodium bisulfite charge on od wood was 0 for DA and 1.5 or 3.0% for SPORL. All substrates produced by both pretreatments (except DA with pretreatment duration of 0) had good enzymatic digestibility of over 80%. However, SPORL produced higher enzymatic digestibility than its corresponding DA pretreatment for all the experiments conducted. As a result, SPORL produced higher ethanol yield from simultaneous saccharification and fermentation of cellulosic substrate than its corresponding DA pretreatment. SPORL was more effective than its corresponding DA pretreatment in reducing energy consumption for postpretreatment wood chip size-reduction. SPORL, with lower energy input and higher sugar and ethanol yield, produced higher sugar and ethanol production energy efficiencies than the corresponding DA pretreatment.

Woody biomass pretreatment for cellulosic ethanol production: Technology and energy consumption evaluation

This review presents a comprehensive discussion of the key technical issues in woody biomass pretreatment: barriers to efficient cellulose saccharification, pretreatment energy consumption, in particular energy consumed for wood-size reduction, and criteria to evaluate the performance of a pretreatment. A post-chemical pretreatment size-reduction approach is proposed to significantly reduce mechanical energy consumption. Because the ultimate goal of biofuel production is net energy output, a concept of pretreatment energy efficiency (kg/MJ) based on the total sugar recovery (kg/kg wood) divided by the energy consumption in pretreatment (MJ/kg wood) is defined. It is then used to evaluate the performances of three of the most promising pretreatment technologies: steam explosion, organosolv, and sulfite pretreatment to overcome lignocelluloses recalcitrance (SPORL) for softwood pretreatment. The present study found that SPORL is the most efficient process and produced highest sugar yield. Other important issues, such as the effects of lignin on substrate saccharification and the effects of pretreatment on high-value lignin utilization in woody biomass pretreatment, are also discussed.

Methionine and selenium yeast supplementation of the maternal diets affects antioxidant activity of breeding eggs

Four hundred fifty 52-wk-old Langshan layer hens (dual-purpose type, an indigenous poultry breed of China) were randomly divided into 9 treatments with 5 replicates in each treatment. Birds were fed corn-soybean diets (0.13 mg of Se/kg) supplemented with 0, 0.30, and 0.60 mg/kg of Se from Se yeast and 3.2, 4.0, and 5.4 g of dl-Met/kg, respectively. Increasing Se yeast supplementation significantly increased Se concentration in the egg yolk (P < 0.01) and the Se concentration of the 3.2 g of Met/kg treatment was higher than those of the 4.0 and 5.4 g of Met/kg treatments. Adding 0.3 mg of Se/kg to the diet significantly increased glutathione peroxidase (GSH-Px) activity in the egg yolk compared with 0 and 0.6 mg of Se/kg (P < 0.01) and increasing Se yeast supplementation significantly increased the GSH-Px activity in the egg albumen (P < 0.01). Increasing Met supplementation significantly decreased the GSH-Px activity in both the yolk and the albumen of the eggs (P < 0.01). Methionine supplemented at 3.2 and 4.0 g/kg significantly increased glutathione concentration in the egg yolk compared with 5.4 g of Met/kg (P < 0.01) and increasing Met supplementation increased the glutathione concentration in the egg albumen. Increasing Met supplementation significantly decreased malondialdehyde concentration in the egg yolk (P < 0.01) and Se supplemented at 0 and 0.6 mg/kg increased the malondialdehyde concentrations in the egg yolk compared with 0.3 mg of Se/kg (P < 0.01). Methionine supplemented at 4.0 and 5.4 g/kg significantly decreased carbonyl concentration compared with 3.2 g of Met/kg. The conclusion was drawn that Se yeast and Met supplementation of the maternal diets could enhance antioxidant activity of breeding eggs.

Comparative study of SPORL and dilute-acid pretreatments of spruce for cellulosic ethanol production

The performance of two pretreatment methods, sulfite pretreatment to overcome recalcitrance of lignocellulose (SPORL) and dilute acid (DA), was compared in pretreating softwood (spruce) for fuel ethanol production at 180 degrees Celsius for 30 min with a sulfuric acid loading of 5% on oven-dry wood and a 5:1 liquor-to-wood ratio. SPORL was supplemented with 9% sodium sulfite (w/w of wood). The recoveries of total saccharides (hexoses and pentoses) were 87.9% (SPORL) and 56.7% (DA), while those of cellulose were 92.5% (SPORL) and 77.7% (DA). The total of known inhibitors (furfural, 5-hydroxymethylfurfural, and formic, acetic and levulinic acids) formed in SPORL were only 35% of those formed in DA pretreatment. SPORL pretreatment dissolved approximately 32% of the lignin as lignosulfonate, which is a potential high-value co-product. With an enzyme loading of 15 FPU (filter paper units) per gram of cellulose, the cellulose-to-glucose conversion yields were 91% at 24h for the SPORL substrate and 55% at 48 h for the DA substrate, respectively.

On energy consumption for size-reduction and yields from subsequent enzymatic saccharification of pretreated lodgepole pine

This study investigated the effects of chemical pretreatment and disk-milling conditions on energy consumption for size-reduction and the efficiency of enzymatic cellulose saccharification of a softwood. Lodgepole pine wood chips produced from thinnings of a 100-year-old unmanaged forest were pretreated by hot-water, dilute-acid, and two SPORL processes (Sulfite Pretreatment to Overcome Recalcitrance of Lignocellulose) at acid charge on oven dry (od) wood of 0% and 2.21%. The pretreated wood chips were then milled using a laboratory disk mill under various solids-loadings and disk-plate gaps to produce substrates for enzymatic hydrolysis. We found that post-chemical-pretreatment size-reduction of forest biomass can decrease size-reduction energy consumption by 20-80% depending on the pretreatment applied under 20% solids-loading and a disk-plate gap of 0.76 mm in milling. SPORL with a sodium bisulfite charge of 8% and sulfuric acid charge of 2.21% on wood was the most effective in decreasing size-reduction energy consumption. Solids-loading had the most significant effect on disk-milling energy. When solids-loading was reduced from 30% to 3%, disk-milling energy could be decreased by more than a factor of 10 for wood chips pretreated by both SPORL and dilute-acid at an acid charge of 2.21%. The enzymatic hydrolysis glucose yields (EHGY) from the substrates produced by all pretreatments were independent of the solids-loading in milling, indicating that these energy savings in size-reduction can be realized without affecting EHGY. When wood chips were pretreated by SPORL with 2.21% acid charge, size-reduction energy consumption was decreased to less than 50 Wh/kg od wood at a practical solids-loading of approximately 10-20%, equivalent to that used in size-reduction of agriculture biomass, with excellent EHGY of about 370 g per kg od wood. Similar effects on size-reduction energy savings and excellent EHGY were also achieved when large disk-plate gaps (up to 1.52 mm studied) were applied in disk-milling of wood chips pretreated by SPORL with acid.

Sulfite pretreatment to overcome recalcitrance of lignocellulose (SPORL) for robust enzymatic saccharification of hardwoods

This study demonstrates sulfite pretreatment to overcome recalcitrance of lignocellulose (SPORL) for robust bioconversion of hardwoods. With only about 4% sodium bisulfite charge on aspen and 30-min pretreatment at temperature 180 degrees C, SPORL can achieve near-complete cellulose conversion to glucose in a wide range of pretreatment liquor of pH 2.0-4.5 in only about 10 h enzymatic hydrolysis. The enzyme loading was about 20 FPU cellulase plus 30 CBU beta-glucosidase per gram of cellulose. The production of fermentation inhibitor furfural was less than 20 mg/g of aspen wood at pH 4.5. With pH 4.5, SPORL avoided reactor corrosion problem and eliminated the need for substrate neutralization prior to enzymatic hydrolysis. Similar results were obtained from maple and eucalyptus.

Effects of heat exposure on muscle oxidation and protein functionalities of pectoralis majors in broilers

This study was conducted to determine the effects of heat stress on pH, lipid peroxidation, protein oxidation, and functionalities of breast meat in broilers. The experimental birds were exposed to 2 temperatures: 24 degrees C (control) and 41 degrees C (heat-stressed) for 0, 1, 2, 3, and 5 h. As compared with control, the pH determinations after slaughter for 30 min and 24 h of chilling, respectively, of the pectoralis major in the heat-stressed groups were significantly lower (P < 0.05). Oxidative stability of i.m. lipid in 3- and 5-h groups (P < 0.01) and protein in 2-, 3-, and 5-h groups (P < 0.01) increased. Protein solubility of pectorilas major decreased after heat exposure. Drip loss and cooking loss were increased in groups from 1 to 5 h of exposure. A reduced strength was noted for myofibrillar protein gels of heat-stressed breasts in exposed groups (P < 0.01); also water-holding capacity of the gels was reduced in treatments of 2, 3, and 5 h (P < 0.01). The results demonstrated that preslaughter exposures to heat reduced the oxidative stability of broiler muscle protein, which might be responsible for decreased protein functionalities such as gelation.

Clinical effects of three types of silicone intubations in repairing lacerations of canaliculus

OBJECTIVE

To evaluate the clinical effects of one-passage, double-passage and circular canalicular intubations in repairing lacerations of canaliculus.

METHODS

A total of 109 eyes in 109 cases of canalicular laceration were repaired with three types of silicone intubations, among which 23 with one-passage canalicular intubation, 51 with double-passage canalicular intubation, and 35 with circular canalicular intubation. The average follow-up period was 12-15 months.

RESULTS

The wound/junction of the lacrimal canaliculi was ruptured in 5 cases (9.80%) of the double-passage group, 3 cases (8.57%) of the circular group, and 8 cases (34.78%) of the one-passage group. The rupture incidence of the one-passage group was significantly higher than that of the other two groups (X(2) equal to 9.416, P less than 0.01). During the intubation, canaliculitis was observed in 12 cases (23.53%) of the double-passage group, while only 3 cases (8.57%) in the circular group and 8 cases (34.78%) in the one-passage group. The circular group had significantly lower incidence of canaliculitis than the other two groups (X(2) equal to 6.095, P less than 0.05). After extubation 6 months after laceration repair, the lacrimal passage remained patent with canalicular irrigation in 46 cases (90.20%) in the double-passage group, 30 cases (85.71%) in the circular group and 15 cases (65.22%) in the one-passage group. Six months after surgery, the canalicular patency in the one-passage group was significantly lower than that of the other two groups (X(2) equal to 7.390, P less than 0.05).

CONCLUSIONS

Circular canalicular intubation is more stable and has less surgical complications than the double-passage and one-passage canalicular intubations. It is also more effective clinically 12-15 months after laceration surgery.

Sulfite pretreatment (SPORL) for robust enzymatic saccharification of spruce and red pine

This study established a novel process using sulfite pretreatment to overcome recalcitrance of lignocellulose (SPORL) for robust and efficient bioconversion of softwoods. The process consists of sulfite treatment of wood chips under acidic conditions followed by mechanical size reduction using disk refining. The results indicated that after the SPORL pretreatment of spruce chips with 8-10% bisulfite and 1.8-3.7% sulfuric acid on oven dry (od) wood at 180 degrees C for 30 min, more than 90% cellulose conversion of substrate was achieved with enzyme loading of about 14.6 FPU cellulase plus 22.5 CBU beta-glucosidase per gram of od substrate after 48 h hydrolysis. Glucose yield from enzymatic hydrolysis of the substrate per 100 g of untreated od spruce wood (glucan content 43%) was about 37 g (excluding the dissolved glucose during pretreatment). Hemicellulose removal was found to be as critical as lignin sulfonation for cellulose conversion in the SPORL process. Pretreatment altered the wood chips, which reduced electric energy consumption for size reduction to about 19 Wh/kg od untreated wood, or about 19 g glucose/Wh electricity. Furthermore, the SPORL produced low amounts of fermentation inhibitors, hydroxymethyl furfural (HMF) and furfural, of about 5 and 1 mg/g of untreated od wood, respectively. In addition, similar results were achieved when the SPORL was applied to red pine. By building on the mature sulfite pulping and disk refining technologies already practiced in the pulp and paper industry, the SPORL has very few technological barriers and risks for commercialization.

Effect of alkali metal cation on the anaerobic hydrolysis and acidogenesis of vegetable waste

Five batch testing scenarios were designed to evaluate the effects of alkali metal cations on anaerobic hydrolysis and acidogenesis. These scenarios were A (c=0 g l(-1)), B (cNa+=25 g l(-1)), C (cNa+=50 g l(-1)), D (cK+=25 g l(-1)), and E (cK+=50 g l(-1), pH 7.0). A solution pH of 7.0 or above favored protein hydrolysis, higher proteinase activity and higher ammonia production. However, such a pH suppressed carbohydrate hydrolysis, as indicated by low alpha-amylase activity. Cation interference at pH 5.0-6.0 seemed not to affect carbohydrate hydrolysis, as showed by the unimpaired alpha-amylase activity at 50 g l(-1) K+. Acidogenesis was more sensitive to alkali metal cations, so acid production and the drop in pH were lowest in a 25-50 g l(-1) Na+, acidic environment (pH 4.0-6.0). It was insensitive to cations when the pH was maintained at 7.0-8.0. When the pH was uncontrolled and decreased freely to acidic values, 25 g l(-1) of cation inhibited the action of the microbes, which rapidly acclimated, as presented by the slow transformation of soluble polymers to soluble metabolites. However, acidogenetic microbes could not easily recover from inhibition by 50 g l(-1) of cation. When the pH was maintained at over 7.0, the microbes were not inhibited by cation (50 g l(-1)) as indicated by the more active acidogenesis. The metabolic pathways to lactate, acetate and alcohols were not fully coupled.

Quantification and reduction of organic sulfur compound formation in a commercial wood pulping process

This study experimentally quantified the formation of organic sulfur compounds in a commercial SuperBatch kraft pulping process using a laboratory pilot-scale digester. The results indicate that wood chips not only can adsorb HS- but also methyl mercaptan (MM) in the black liquor used for pretreatment during the two pretreatment stages. The absorption rate of MM is much faster than that of HS-. In the third stage of SuperBatch pulping, the rate of formation of MM and dimethyl sulfide (DMS) is very similar to that found in conventional batch kraft pulping processes. The study examined the applicability of the phase transition cooking (PTC) concept for reducing organic sulfur compounds in pulping, previously developed in laboratory batch pulping using a bomb-type digester, in a SuperBatch process. It was confirmed that there is a phase transition point (PTP) corresponding to PTC in SuperBatch pulping beyond which further delignification significantly increases the formation of volatile organic sulfur compounds. The results indicate that a 40% reduction of TRS formation can be achieved by using PTC.

Synchronous, dual-wavelength, injection-seeded amplification of 5-ns pulses in a flash-lamp-pumped Ti:sapphire laser

The outputs of two cw diode lasers are coupled into a flash-lamp-pumped Ti:sapphire laser cavity for regenerative amplification. Slices of each seed beam are simultaneously trapped in the cavity and amplified for approximately 33 round trips. The output is a 4.7-ns pulse, the total pulse energy is 110 mJ, and linewidths are only 50% greater than the Fourier-transform limit. The timing jitter between the pulses at the two wavelengths is less than +/-75 ps , and their relative energy is controlled by adjustment of the seed power of the cw diode lasers. Gain competition between the two frequencies does not lead to instabilities.