Recycling drinking water treatment sludge in construction and building materials: A review

Drinking water treatment sludge (DWTS) is a by-product of water treatment, and it is difficult to recycle to high value and poses potential environmental risks. Recycling DWTS into cement-based materials is an effective measure to achieve its high-volume utilization and reduce its environmental load. DWTS is rich in silica-alumina phases and has potential pozzolanic activity after drying, grinding and calcination, giving it similar properties to traditional supplementary cementitious materials. Adjusting the sludge production process and coagulant type will change its physical and chemical properties. Adding a small amount of DWTS can generate additional hydration products and refine the pore structure of the cement sample, thus improving the mechanical properties and durability of the sample. However, adding high-volume DWTS to concrete causes microstructural deterioration, but it is feasible to use high-volume DWTS to produce artificial aggregates, lightweight concrete, and sintered bricks. Meanwhile, calcined DWTS has similar compositions to clay, which makes it a potential raw material for cement clinker production. Cement-based materials can effectively solidify heavy metal ions in DWTS, and alkali-activated binders, magnesium-based cement, and carbon curing technology can further reduce the risk of heavy metal leaching. This review provides support for the high-value utilization of DWTS in cement-based materials and the reduction of its potential environmental risks.

Upcycling textile sludge into magnesium oxychloride cement: Physical properties, microstructure, and leaching behavior

Textile sludge is a by-product produced during the wastewater treatment process in the textile printing and dyeing industry. Textile sludge is rich in heavy metal elements, which makes it a potential risk to the surrounding environment. This study designs a magnesium oxychloride cement (MOC) components to solidify harmful substances in textile sludge and studies the influence of textile sludge ash (TSA) on the mechanical properties and microstructure of MOC samples. The results indicated that adding 5 %-20 % TSA is beneficial for increasing the compressive strength of air-cured MOC paste and improving its water resistance. Meanwhile, the MOC sample shows volume expansion in 168 h, which is related to the further hydration of residual MgO. Incorporating 10 %-20 % TSA substantially increased the volume expansion ratio of the mixture compared to plain MOC sample. In addition, the porosity of TSA-modified MOC after water curing did not change significantly compared to the sample before water curing, while the pore structure of plain MOC after water curing significantly coarsened. This is mainly because TSA reacts with MOC and generates Mg-Al-Cl-Si-H and Mg-Cl-Si-H gels, consequently improving the water stability of MOC sample. At the nanoscale, the 3/5-phase crystal and unreacted MgO content in the 15 % TSA-modified MOC sample is relatively reduced by 7.79 % and 25 %, respectively, compared to the plain sample, but the 13 % gel phase is detected. In addition, the MOC component can effectively solidify heavy metal elements in textile sludge. For the leachate of 20 % TSA-modified MOC paste, the Ni element is not detected, and its solidifying effect on heavy elements such as Zn and Mn exceeded 99 %.

[Effect of preoperative anterior bony impingement on lateral collateral ankle ligament reconstruction]

Objective: To explore whether the combination of anterior bony impingement before surgery will affect the efficacy of the lateral collateral ankle ligament reconstruction surgery in patients with chronic ankle instability (CAI). Methods: A prospective cohort study. Patients with CAI who underwent lateral collateral ankle ligament reconstruction from January 2014 to October 2017 in the Department of Sports Medicine, Huashan Hospital, Fudan University were enrolled in this study. The patients were divided into no bony impingement group (NI group) and bony impingement group (BI group) according to the presence of bone impingement in front of the ankle during the operation. Preoperative American Orthopedic Foot and Ankle Society (AOFAS) score, Karlsson ankle functional socre (KAFS), Tegner score, visual analogue scale (VAS) of pain were extracted and were reevaluated at least 2 years after surgery as well as imaging evaluation of ankle. Results: A total of 59 patients were enrolled in this study. There were 29 patients in the NI group, 23 males and 6 females with a mean age of (28.4±7.1) years. And there were 30 cases in the BI group, 28 males and 2 females with a mean age of (31.9±8.6) years. The AOFAS, KAFS and Tegner scores in NI group increased from 65.8±10.6, 65.9±10.1 and 3.0 (3.0, 4.0) before the operation to 97.5±4.3, 97.8±4.7 and 6.0(5.0,6.0) after the operation, respectively; and the VAS decreased from 3.0(3.0, 4.0) to 0(0, 0); there were significant differences in those indexes before and after the operation (all P<0.05). The scores of AOFAS, KAFS and Tegner in BI group increased from 65.2±11.0, 64.2±10.0 and 3.0(3.0, 4.0) before the operation to 97.1±4.3, 97.3±4.3 and 5.0(4.0, 6.0) post the operation, respectively; and the VAS scores decreased from 3.0(3.0, 5.0) to 0(0, 1.0); there were significant differences in up-mentioned indexes before and after the surgery (all P<0.05). There was no significant differences in baseline and preoperative clinical function scores between the two groups (all P>0.05). No significant difference was found in postoperative AOFAS, KAFS and VAS scores between the two groups (all P>0.05), while postoperative Tegner score in the NI group was significantly higher than that in the BI group [6.0(5.0, 6.0) vs 5.0(4.0, 6.0), P=0.026]. Imaging evaluation of all patients showed that the reconstructed ligament was clearly visible, and the intraarticular injuries existing before surgery showed obvious signs of healing. Conclusion: Ankle lateral collateral ligament reconstruction for CAI with or without anterior bony impingement results in similar outcomes in ankle function, stability and pain levels.

Antitumor efficacy of a recombinant EGFR-targeted fusion protein conjugate that induces telomere shortening and telomerase downregulation

OBJECTIVE

To prepare a recombinant EGFR-targeted fusion protein drug conjugate acting on telomere and telomerase; and evaluate its antitumor efficacy.

METHODS

We prepared a recombinant fusion protein Fv-LDP-D3 which consists of the Fv fragment of an anti-EGFR monoclonal antibody (MAb), the apoprotein of lidamycin (LDP), and the third domain (D3) of human serum albumin (HSA); then generated the conjugate Fv-LDP-D3∼AE by integrating the active enediyne chomophore (AE) of lidamycin. Accordingly, in vitro and in vivo experiments were performed.

RESULTS

As shown, Fv-LDP-D3 specifically bound to EGFR highly-expressing cancer cells and intensely entered K-Ras mutant cells via enhanced macropinocytosis. By in vivo imaging, Fv-LDP-D3 displayed intense accumulation and persistent retention in tumor-site. Furthermore, the conjugate Fv-LDP-D3∼AE displayed highly potent cytotoxicity to cancer cells with IC₅₀ at 0.1 nM level. The conjugate induced telomere shortening and downregulation of telomerase and EGFR pathway related proteins. Fv-LDP-D3∼AE exhibited prominent antitumor efficacy against human colorectal cancer xenograft accompanying with significant increase of serum IFN-β in athymic mice.

CONCLUSION

The recombinant fusion protein conjugate that exhibits the capability of tumor-targeting drug delivery can induce telomere shortening and telomerase downregulation. The investigation may lay the foundation for the development of MAb-HSA domain-based fusion protein drug conjugates.

[Correlation between serum CD147 and carotid intraplaque hemorrhage]

Objective: Intraplaque hemorrhage (IPH) is one of the most important causes of ischemic stroke. The purpose of this study was to explore the association between carotid IPH and CD147, which may be the serum marker related to IPH. Methods: Serum samples were collected from 68 patients with carotid artery stenosis from April to September 2004. 3.0T MRI with the 8 channel surface coil was used to scan carotid artery. Images was processed by MRI-PlaqueView. The integrity of lipid, IPH, calcified components and fibrous cap in the plaque was analysed qualitatively and quantitatively. The correlation and difference analysis among serum CD147 and plaque components were carried out. Results: Serum CD147 level in IPH positive was higher than that in IPH negative, 5 510.1 vs 4 648.0 (P=0.04). There was no significant correlation among serum CD147 and the quantitative parameters of lipid, IPH and calcification in carotid plaque and fibrous cap rupture. Serum CD147 in patients using statins was lower than that in patients not using statins, 4 914.0 vs 5 926.7 (P<0.01). Serum total cholesterol and LDL were positively correlated with serum CD147. In patients without statin, serum CD147 had a better diagnostic value for carotid IPH (AUC=0.81, P=0.04, 95% CI 0.62-0.99). Conclusion: Serum CD147 would probably be one biomarker of IPH and shows good diagnostic value of carotid IPH in the specific population.

Role of iron in lung injury-induced by hyperoxia

Iron is essential to life due to its unusual flexibility in serving as both an electron donor and acceptor. However, free iron can damage tissues by catalyzing the conversion of hydrogen peroxide to free-radical ions that attack lipids, proteins and DNA. Hyperoxia-induced lung injury (HILI) occurs when breathing elevated partial pressure of oxygen (usually > 0.5 atmospheres absolute) for extended periods. A few studies have shown that iron and proteins related to iron metabolism are closely related to HILI, and iron chelation may exert protective effects on HILI. As a rate-limiting enzyme in the degradation of heme, heme oxygenases (HOs) play a crucial role in the iron metabolism. Although some studies have been conducted to investigate the role of HOs in the pathogenesis of HILI, findings still conflict, and HOs of different isoforms may function differently in the pathogenesis of HILI. On the available findings, there might be a beneficial threshold of HO-1 expression in HILI. More studies are required to confirm the above findings and to provide evidence for the clinical treatment of HILI by iron chelation.

Current status of decompression illness in China: analysis of studies from 2001-2011

OBJECTIVE

To analyze the studies on decompression illness (DCI) in China in the past 10 years.

METHODS

We searched three Chinese databases and collected studies on DCI for further analysis. On the basis of findings, we proposed the issues on DCI in China.

RESULTS

There are more than 50,000 active divers in China, the majority of whom are fishing divers. Among them, the incidence of DCI is still at a high level because they have little or no knowledge of diving and diving medicine, the quality of diving equipment is poor, and divers generally do not follow the regulations of diving. There are few dive physicians in China, and the general clinicians have poor knowledge about, or pay little attention to, dive medicine. This might be the major cause of the poor quality of studies on DCI. There is no consensus in the classification of DCI and treatment tables for DCI treatment. These are factors affecting systemic review and further meta-analysis of available studies on DCI.

CONCLUSION

It is imperative to generalize knowledge in not only divers and diving-related practitioners but general practitioners as well.

Papulonecrotic tuberculid--a rare skin manifestation in a patient with pulmonary tuberculosis

Papulonecrotic tuberculid (PNT), a cutaneous manifestation of tuberculosis, is rare even in areas endemic for tuberculosis such as Taiwan. Concomitant pulmonary tuberculosis is uncommon in patients with PNT. We describe a patient with rare skin manifestations and simultaneous pulmonary tuberculosis. This 48-year-old woman had suffered from productive cough for 4 months, and pea-sized papules with central umbilication were noted over the extensor surface of her four extremities and lower abdomen 1 month prior to admission to our hospital. Chest roentgenography showed reticulonodular lesions with small cavitation over the lower right lung field, and sputum culture yielded Mycobacterium tuberculosis complex. PNT was diagnosed using the skin biopsy results and the papules healed with scar formation after antituberculous therapy.

Diaphragm mechanics in dogs with unilateral emphysema

We studied dogs with unilateral papain-induced emphysema to answer two questions: (1) Do emphysema lung-apposed hemidiaphragm (DiE) and normal lung-apposed hemidiaphragm (DiN) have equal capacities for lowering lung surface pressure? and (2) Are side-to-side differences in intrathoracic pressure the result of unequal force outputs by DiE and DiN or are they caused by differences in their mechanical efficiency as pressure generators? After the airways of the emphysematous and normal lungs were intubated with a dual lumen endotracheal tube, both phrenic nerves were maximally stimulated at rates between 1 and 50 Hz and the changes in airway occlusion pressure (delta PaoE,N) and diaphragm length (sonomicrometry) were recorded. In all animals, delta PaoN exceeded delta PaoE. Differences in pressure ranged from 1.2 +/- 0.6 cm H2O during a twitch to 6.0 +/- 2.9 cm H2O during a 50-Hz tetanus. Midcostal bundles of DiE shortened less than corresponding bundles of DiN, but both reached the same active length relative to their optimal lengths, which were measured in vitro. There was no significant difference in fiber type distribution, fiber cross-sectional area, or maximal isometric tetanic tensions among midcostal regions of DiE and DiN. We conclude that unilateral hyperinflation impairs the mechanical efficiency of the apposing hemidiaphragm as a pressure generator.

[Changes of Leu-enkephalin in striatum and hypothalamus of rats during hyperbaric oxygen exposure]

The purpose of this study is to investigate the changes of Leu-Enkephalin (L-Enk) content in striatum and hypothalamus of rats during hyperbaric (HBO) oxygen exposure. Thirty-two male rats in the experiment were randomly divided into four groups: normobaric air group, normoxic hyperbaric nitrox group, nonconvulsion HBO group and convulsion HBO group. L-Enk content in striatum and hypothalamus was determined by radioimmunoassay. The results show that L-Enk content in the striatum and hypothalamus of rats exposed to hyperbaric oxygen environment were markedly higher than that of rats exposed to normobaric air and normoxic hyperbaric nitrox. The experimental results suggest that the elevation of L-Enk content in striatum and hypothalamus shows a positive relationship with the HBO exposure duration of animals and that there was no marked relationship with normoxic hyperbaric nitrox environment and compression-decompression method.

Predictability of ventilatory muscle optimal length based on excised dimensions

The purpose of the present study was to assess the relationship between excised length (unstressed length of excised muscle; Lex) and optimal force-generating length (Lo) in a variety of respiratory muscles, with the goal of establishing a reliable method whereby Lo could be rapidly and easily estimated with a high level of accuracy. Experiments were conducted on 111 muscle bundles obtained from 18 mongrel dogs. Segments of costal diaphragm, parasternal intercostal, scalene, sternomastoid, triangularis sterni, rectus abdominis, external oblique, and transversus abdominis muscles were studied. We noted a linear relationship between the distance measured between two fixed points in excised bundles (Lex) and at the muscles' Lo. Correlation coefficients ranged from 0.83 (P less than 0.01) for the transversus abdominis to 0.92 (P less than 0.01) for the triangularis sterni and external oblique muscles. Pooled Lex for all muscles averaged 61.4 +/- 6.3% (SD) Lo, with specific values ranging from 55.5 +/- 3.9% Lo for triangularis sterni bundles to 63.0 +/- 5.1% Lo for external oblique bundles. In three additional dogs, we verified the usefulness of this relationship and prospectively estimated Lo from excised length in 10 costal diaphragm bundles and 10 transversus abdominis bundles and then measured Lo directly. Predicted Lo averaged 100.0 +/- 6.0% Lo for diaphragm and 97.6 +/- 5.9% Lo for transversus abdominis muscle. We conclude that Lo can be conveniently and accurately estimated from excised dimensions. This rapid estimation technique should prove valuable for future studies in respiratory muscle physiology.

Urinary ANP, ADH, and electrolyte excretion during saturation-excursion diving to pressures equivalent to 250 and 300 m

Four male divers were exposed to an environment of 26 and 31 atm abs He-O2 for 2 days. Urine was collected during the day (0700-1900 h) and at night (1900-0700 h) before (predive 1 atm abs air), during, and after (decompression and postdive 1 atm abs air) the exposure. Urine flow increased markedly and was mostly attributable to the urine flow during 1900-0700 h. The secretion of atrial natriuretic polypeptide (ANP) increased only at night during hyperbaria. On the other hand, the secretion of antidiuretic hormone (ADH) was suppressed, but increased during compression and the early phase of hyperbaric exposure before it decreased. Linear regression analysis showed that urinary excretion of ANP was correlated significantly with urine flow (r = 0.88, P less than 0.01) and that excretion of ADH negatively correlated with urine flow (r = -0.61, P less than 0.01). Urinary excretion of Na, Cl, Ca, and Mg increased significantly at night during hyperbaria, whereas there was no consistent change in the excretion of K and P. These results suggest that both stimulated ANP secretion and suppressed ADH secretion correlate with the increase of urine and that nocturia is mostly attributable to stimulated ANP secretion. We observed that urinary excretion of ANP increased significantly as early as during the compression phase, which suggested that ANP plays a decisive role in the early diuresis.

Mechanics of acutely shortened canine diaphragm muscle in vitro

Acute changes in lung volume, as might be seen in an airway-obstructed patient, may lead to different amounts of shortening of the various inspiratory muscles, of which the diaphragm is the most important. The purpose of this study is to investigate the twitch and contractile characteristics of acutely shortened canine diaphragm muscle in vitro during isometric contraction. We found that with diaphragmatic muscle shortening from Lo (optimal length, defined as being that length at which peak twitch tension was generated) to 70% Lo, the time-to-peak tension, half relaxation time and twitch tension were significantly reduced. The force-frequency curves, obtained from different muscle lengths, disclosed that shorter muscles generate disproportionately less force during low-frequency stimulation. These factors may, at least in part, contribute to the vulnerability to fatigue of those with shorter diaphragmatic muscle length.

Mechanical role of expiratory muscle recruitment during eupnea in supine anesthetized dogs

To assess the mechanical role of the expiratory musculature during eupnea, we recorded the electromyographic (EMG) activity of the triangularis sterni, the external oblique, and the transversus abdominis in eight supine lightly anesthetized dogs and have measured the volume generated by the phasic activation of the expiratory muscles. Activation of the expiratory muscles was invariably associated with a decrease in lung volume below the relaxed position of the respiratory system, a volume equal to 41.3 +/- 8.4 ml. This volume represented roughly 20% of tidal volume generated during spontaneous breathing. The fractional expiratory contribution to the tidal volume was unrelated to the size of the animal. Traction on the forelimbs (limb extension), however, tended to enhance the phasic expiratory activation of both the triangularis sterni and the transversus abdominis in the majority of animals. Moreover, after limb extension, the fractional contribution of tidal volume attributed to the phasic activation of the expiratory muscles increased in all but one animal. During spontaneous breathing with the forelimbs extended, roughly 25% of tidal volume was found to be due directly to phasic expiratory muscle contraction. The present observations firmly establish that in supine lightly anesthetized dogs breathing at rest the expiratory component of tidal volume represents a substantial contribution.