Gastric and colorectal cancer incidence attributable to dietary factors in Korea.

Background: Dietary factors play a role in the etiology of gastrointestinal cancer. We aimed to estimate the burden of gastric and colorectal cancer that can be attributable to dietary factors in adults aged 20 years and older in Korea in 2018. Methods: Dietary intakes in 2000 were estimated using data from the 2001, 2005, and 2007-2018 Korea National Health and Nutrition Examination Survey (KNHANES). For counterfactual scenarios, the optimal level of intake suggested by the Global Burden of Disease (GBD) study was used if it was available. Otherwise, the average intake values of reference groups among published studies globally were used. Relative risks (RRs) were pooled through dose-response meta-analyses of Korean studies. Results: In Korea in 2018, an estimated 18.6% of gastric cancer cases and 34.9% of colorectal cancer cases were attributed to the combined effect of evaluated dietary factors. High intake of salted vegetables accounted for 16.0% of gastric cancer cases, followed by salted fish at 2.4%. Low intakes of whole grains (16.6%) and milk (13.7%) were leading contributors to colorectal cancer cases, followed by high intakes of processed meat (3.1%) and red meat (5.9%), and a low intake of dietary fiber (0.5%). Conclusions: These results suggest that a considerable proportion of gastric and colorectal cancer incidence might be preventable by healthy dietary habits in Korea. However, further research is needed to confirm the associations between dietary factors and gastric and colorectal cancers in Korea and to formulate and apply effective cancer prevention strategies to Koreans.

National Follow-up Survey of Preventable Trauma Death Rate in Korea.

BACKGROUND: The preventable trauma death rate survey is a basic tool for the quality management of trauma treatment because it is a method that can intuitively evaluate the level of national trauma treatment. We conducted this study as a national biennial follow-up survey project and report the results of the review of the 2019 trauma death data in Korea. METHODS: From January 1, 2019 to December 31, 2019, of a total of 8,482 trauma deaths throughout the country, 1,692 were sampled from 279 emergency medical institutions in Korea. All cases were evaluated for preventability of death and opportunities for improvement using a multidisciplinary panel review approach. RESULTS: The preventable trauma death rate was estimated to be 15.7%. Of these, 3.1% were judged definitive preventable deaths, and 12.7% were potentially preventable deaths. The odds ratio for preventable traumatic death was 2.56 times higher in transferred patients compared to that of patients who visited the final hospital directly. The group that died 1 hour after the accident had a statistically significantly higher probability of preventable death than that of the group that died within 1 hour after the accident. CONCLUSION: The preventable trauma death rate for trauma deaths in 2019 was 15.7%, which was 4.2%p lower than that in 2017. To improve the quality of trauma treatment, the transfer of severe trauma patients to trauma centers should be more focused.

Neurological Prognostication Using Raw EEG Patterns and Spectrograms of Frontal EEG in Cardiac Arrest Patients.

PURPOSE: We investigated which raw EEG and spectrogram patterns in frontal EEG predict poor neurological outcomes in patients with hypoxic ischemic encephalopathy after cardiac arrest. METHODS: This multicenter, prospective, observational study included 52 patients with anoxic brain injury after cardiac arrest. Raw EEGs and spectrograms (color density spectral arrays) measured with hardwired frontal EEG monitoring were used to predict poor prognosis. Neurological variables upon admission, raw EEG patterns, including highly malignant and malignant EEG patterns, and changes in frequency and amplitude from color density spectral arrays were investigated. RESULTS: All patients exhibiting highly malignant EEG patterns died, and malignant EEG patterns were significant predictors of poor prognosis as the area under the receiver operating characteristic curve was 0.83 to 0.86. Irregular high-voltage waves in the high-frequency beta band in continuous background EEGs were associated with poor prognosis ( P = 0.022). Malignant EEG patterns including high-voltage and high-frequency beta waves were significantly stronger predictors of poor prognosis than the absence of ventricular fibrillation and pupil reflex, delayed length of anoxic time, and lower Glasgow coma scale score (odds ratio, 9; P = 0.035). Compared with prognostication using malignant EEG patterns alone, the area under the receiver operating characteristic curve of results incorporating high-voltage and high-frequency beta waves was 0.84 (vs. 0.83) at day 1, 0.88 (vs. 0.85) at day 2, 0.92 (vs. 0.86) at day 3, and 0.99 (vs. 0.86) at day 4. CONCLUSIONS: Frontal EEG monitoring is useful for predicting poor neurological outcomes. Brain function monitoring using both raw EEG patterns and color density spectral arrays is more helpful for predicting poor prognosis than raw EEG alone.

Encapsulation of 3D plasmonic nanostructures with ultrathin hydrogel skin for rapid and direct detection of toxic small molecules in complex fluids.

Nanogap-rich 3D plasmonic nanostructures provide enhanced molecular Raman fingerprints in a nondestructive and label-free manner. However, the molecular detection of small target molecules in complex fluids is challenging due to nonspecific protein adsorption, which prevents access of the target molecules. Therefore, the molecular detection for complex mixtures usually requires a tedious and time-consuming pretreatment of samples. Herein, we report the encapsulation of 3D plasmonic nanostructures with an ultrathin hydrogel skin for the rapid and direct detection of small molecules in complex mixtures. To demonstrate the proof of concept, we directly detect pesticide dissolved in milk without pretreatment. This detection is enabled by the selective permeation of target molecules into the 3D mesh of the hydrogel skin and the adsorption onto plasmonic hotspots, accompanied by the rejection of large adhesive proteins and colloids. The high sensitivity of nanogap-rich plasmonic nanostructures in a conjunction with the molecular selection of the hydrogel skin enables the fast and reliable detection of tricyclazole in whole milk with a limit of detection as low as 10 ppb within 1 h. We believe that this plasmonic platform is highly adaptable for in situ and on-site detection of small molecules in various complex mixtures including foods, biological fluids, and environmental fluids.

Clinical Guidance for Point-of-Care Ultrasound in the Emergency and Critical Care Areas after Implementing Insurance Coverage in Korea.

Point-of-care ultrasound (POCUS) is a useful tool that is widely used in the emergency and intensive care areas. In Korea, insurance coverage of ultrasound examination has been gradually expanding in accordance with measures to enhance Korean National Insurance Coverage since 2017 to 2021, and which will continue until 2021. Full coverage of health insurance for POCUS in the emergency and critical care areas was implemented in July 2019. The National Health Insurance Act classified POCUS as a single or multiple-targeted ultrasound examination (STU vs. MTU). STU scans are conducted of one organ at a time, while MTU includes scanning of multiple organs simultaneously to determine each clinical situation. POCUS can be performed even if a diagnostic ultrasound examination is conducted, based on the physician's decision. However, the Health Insurance Review and Assessment Service plans to monitor the prescription status of whether the POCUS and diagnostic ultrasound examinations are prescribed simultaneously and repeatedly. Additionally, MTU is allowed only in cases of trauma, cardiac arrest, shock, chest pain, and dyspnea and should be performed by a qualified physician. Although physicians should scan all parts of the chest, heart, and abdomen when they prescribe MTU, they are not required to record all findings in the medical record. Therefore, appropriate prescription, application, and recording of POCUS are needed to enhance the quality of patient care and avoid unnecessary cut of medical budget spending. The present article provides background and clinical guidance for POCUS based on the implementation of full health insurance coverage for POCUS that began in July 2019 in Korea.

Effect of trophic conditions on microalga growth, nutrient removal, algal organic matter, and energy storage products in Scenedesmus (Acutodesmus) obliquus KGE-17 cultivation.

This study compared the performance of microalga growth, nutrient removal, algal organic matter, and energy storage products in mixotrophic, photoautotrophic, and heterotrophic conditions. Scenedesmus obliquus was used as a model species. Mixotrophic condition showed the highest specific growth rate of 0.96 d-1 as well as the fastest nitrogen and phosphorus removal rate of 85.17 mg-N g-cell-1 day-1 and 11.49 mg-P g-cell-1 day-1, respectively, compared with photoautotrophic and heterotrophic conditions. Mixotrophic microalgae had relatively higher carbohydrates and lipids contents (21.8 and 24.0%) than photoautotrophic and heterotrophic conditions. Meanwhile, algal organic matter (AOM) in the medium was produced at the highest level under photoautotrophic condition. Mixotrophic condition was more efficient in terms of microalga growth, nutrient removal, production of energy storage products, and suppression of AOM, and would be adaptable for wastewater treatment process.

Continuous neuromuscular blockade infusion for out-of-hospital cardiac arrest patients treated with targeted temperature management: A multicenter randomized controlled trial.

INTRODUCTION: The aim of this trial was to investigate the effect of a continuous infusion of a neuromuscular blockade (NMB) in comatose out-of-hospital cardiac arrest (OHCA) subjects who underwent targeted temperature management (TTM). METHODS: In this open-label, multicenter trial, subjects resuscitated from OHCA were randomly assigned to receive either NMB (38 subjects) or placebo (43 subjects) for 24 hours. Sedatives and analgesics were given according to the protocol of each hospital during TTM. The primary outcome was serum lactate levels at 24 hours after drug infusion. The secondary outcomes included in-hospital mortality, a poor neurological outcome at hospital discharge, changes in lactate levels, changes in the PaO2:FiO2 ratio over time and muscle weakness as assessed by the Medical Research Council (MRC) scale. RESULTS: Eighty-one subjects (NMB group: median age, 65.5 years, 30 male patients; placebo group: median age, 61.0 years, 29 male patients) were enrolled in this trial. No difference in the serum lactate level at 24 hours was observed between the NMB (2.8 [1.2-4.0]) and placebo (3.6 [1.8-5.2]) groups (p = 0.238). In-hospital mortality and a poor neurologic outcome at discharge did not differ between the two groups. No significant difference in the PaO2:FiO2 ratio over time (p = 0.321) nor the MRC score (p = 0.474) was demonstrated. CONCLUSIONS: In OHCA subjects who underwent TTM, a continuous infusion of NMB did not reduce lactate levels and did not improve survival or neurological outcome at hospital discharge. Our results indicated a limited potential for the routine use of NMB during early TTM. However, this trial may be underpowered to detect clinical differences, and future research should be conducted.

A low-noise silicon nitride nanopore device on a polymer substrate.

We report a novel low-noise nanopore device employing a polymer substrate. The Si substrate of a fabricated Si-substrate-based silicon nitride (Si3N4) membrane was replaced with a polymer substrate. As such, laser machining was used to make a micro-size hole through the polyimide (PI) substrate, and a thin Si3N4 membrane was then transferred onto the PI substrate. Finally, a nanopore was formed in the membrane using a transmission electron microscope for detection of biomolecules. Compared to the Si-substrate-based device, the dielectric noise was greatly reduced and the root-mean-square noise level was decreased from 146.7 to 5.4 pA. Using this device, the translocation of double-strand deoxyribonucleic acid (DNA) was detected with a high signal/noise (S/N) ratio. This type of device is anticipated to be available for future versatile sequencing technologies.

Optic nerve sheath diameter measured using early unenhanced brain computed tomography shows no correlation with neurological outcomes in patients undergoing targeted temperature management after cardiac arrest.

AIM: Previous studies indicated that the optic nerve sheath diameter (ONSD) measured using brain computed tomography (CT) is a prognostic factor for poor neurological outcome after cardiac arrest. However, these studies were retrospective or included a small sample size. We performed a prospective multi-centre observational study to investigate the correlation between the ONSD on early brain CT and neurological outcomes in patients undergoing targeted temperature management (TTM). METHODS: This study used data from the Korean Hypothermia Network prospective registry between November 2015 and October 2016. Out-of-cardiac arrest patients who underwent brain CT within 2 h after return of spontaneous circulation (ROSC) were included. The primary endpoint was neurological outcomes at 6 months (cerebral performance category; CPC); the secondary outcome was hospital mortality. The ONSD was measured using unenhanced brain CT images. RESULTS: In total, 374 patients were included from 18 hospitals, and 329 underwent CT within 2 h after ROSC. Six months after cardiac arrest, good (CPC 1-2) and poor (CPC 3-5) neurological outcomes were observed in 99 (30.09%) and 230 (69.91%) patients, respectively. There was no significant difference in the ONSD between groups (good outcome group: 5.61 ±â€¯0.59 mm, poor outcome group: 5.69 ±â€¯0.79 mm; p = 0.275), nor between discharged patients who survived and those with hospital mortality (5.63 ±â€¯0.64 mm and 5.70 ±â€¯0.67 mm, respectively, p = 0.399). CONCLUSION: The ONSD on initial brain CT after ROSC was not correlated with neurological outcome at 6 months in patients who underwent TTM.

Successful Use of Targeted Temperature Management After Repair of Myocardial Rupture from Blunt Chest Trauma: A Case Report.

Targeted temperature management (TTM) improves survival and neurological outcome after nontraumatic cardiac arrest. However, TTM is not used widely after traumatic cardiac arrest because of concerns that it might exacerbate bleeding. We report the use of postarrest TTM after repair of blunt myocardial rupture. A 48-year-old man was admitted after being rescued from a major traffic accident by the local emergency service. Focused sonography showed pericardial fluid without cardiac tamponade. Computed tomography showed a large hematoma in the anterior mediastinum associated with hemopericardium. The patient developed cardiac arrest during the operative preparations. Repeat bedside sonography revealed a large pericardial effusion and signs of cardiac tamponade. Spontaneous circulation was restored after ultrasound-guided pericardiocentesis. His Glasgow Coma Scale score was 3. The patient was transported promptly to the operating room and underwent median sternotomy without cardiopulmonary bypass. A rupture of the junction of the superior vena cava/right atrium and left atrial appendage was detected and was closed by direct suturing. Immediately after return to the intensive care unit, we performed TTM (target body temperature 34.5°C) using a surface-cooling device at 4 hours postarrest. TTM was maintained for 24 hours and controlled gradual rewarming was then initiated. He regained consciousness 36 hours postrewarming with limited speech ability. The patient recovered with no further cardiac events and was discharged 3 weeks after admission, with no other serious complications. The patient was neurologically intact (cerebral performance category 1) at 6 months of follow-up. This case demonstrates the potential benefit and applicability of postarrest TTM in patients after repair of blunt myocardial rupture.

Nutritional Care of Gastric Cancer Patients with Clinical Outcomes and Complications: A Review.

The incidence and mortality of gastric cancer have been steadily decreased over the past few decades. However, gastric cancer is still one of the leading causes of cancer deaths across many regions of the world, particularly in Asian countries. In previous studies, nutrition has been considered one of significant risk factors in gastric cancer patients. Especially, malnourished patients are at greater risk of adverse clinical outcomes (e.g., longer hospital stay) and higher incidence of complications (e.g., wound/infectious complications) compared to well-nourished patients. Malnutrition is commonly found in advanced gastric cancer patients due to poor absorption of essential nutrients after surgery. Therefore, nutritional support protocols, such as early oral and enternal feeding, have been proposed in many studies, to improve unfavorable clinical outcomes and to reduce complications due to delayed application of oral nutritional support or parental feeding. Also, the supplied with enternal immune-enriched diet had more benefits in improving clinical outcomes and fewer complications compared to a group supplied with control formula. Using nutritional screening tools, such as nutritional risk index (NRI) and nutritional risk screening (NRS 2002), malnourished patients showed higher incidence of complications and lower survival rates than non-malnourished patients. However, a long-term nutritional intervention, such as nutritional counseling, was not effective in the patients. Therefore, early assessment of nutritional status in patients using a proper nutritional screening tool is suggested to prevent malnutrition and adverse health outcomes. Further studies with numerous ethnic groups may provide stronger scientific evidences in association between nutritional care and recovery from surgery in patients with gastric cancer.

Decrease in the urine cotinine concentrations of Korean non-smokers between 2009 and 2011 following implementation of stricter smoking regulations.

This study aimed to determine if there was an association between the implementation of smoking regulation policies and the urine cotinine concentrations of Korean non-smokers. The subjects of this study were 4612 non-smoking Korean citizens (aged 19 or older) selected from the first stage of the Korean National Environmental Health Survey conducted by the National Institute of Environmental Research from 2009 to 2011. Cotinine concentrations in urine were measured by GC-MS (limit of detection: 0.05 ng/mL). Changes in the urine cotinine concentration were analyzed using a weighted general linear model and linear regression and values were shown as geometric mean (GM). The GM urine cotinine concentration decreased over time (2.92 ng/mL in 2009, 1.93 ng/mL in 2010, and 1.25 ng/mL in 2011). The total decrease in the subjects' urine cotinine concentration between 2009 and 2011 was 2.79 ng/mL, representing a relative decrease of 54.7%. The decrease in GM urine cotinine concentration in each subgroup ranged from 2.17 ng/mL to 3.29 ng/mL (relative decreases of 46.4% and 62.8%, respectively), with the largest absolute reductions in subjects in the following groups: females, aged 40-49 years, detached residence type, no alcohol consumption, employed, secondhand smoke exposure. All groups had negative regression coefficients, all of which were significant (p < 0.001). Our results provide indirect indicators of the effectiveness of smoking regulation policies including the revision of the National Health Promotion Act in Korea.

Evaluating integrated strategies for robust treatment of high saline piggery wastewater.

In this study, we integrated physicochemical and biological strategies for the robust treatment of piggery effluent in which high levels of organic constituents, inorganic nutrients, color, and salts remained. Piggery effluent that was stabilized in an anaerobic digester was sequentially coagulated, micro-filtered, and air-stripped prior to biological treatment with mixotrophic algal species that showed tolerance to high salinity (up to 4.8% as Cl(-)). The algae treatment was conducted with continuous O2 supplementation instead of using the combination of high lighting and CO2 injection. The microalga Scenedesmus quadricauda employed as a bio-agent was capable of assimilating both nitrogen (222 mg N g cell(-1) d(-1)) and phosphorus (9.3 mg P g cell(-1) d(-1)) and utilizing dissolved organics (2053 mg COD g cell(-1) d(-1)) as a carbon source in a single treatment process under the heterotrophic growth conditions. The heterotrophic growth of S. quadricauda proceeded rapidly by directly incorporating organic substrate in the oxidative assimilation process, which coincided with the high productivity of algal biomass, accounting for 2.4 g cell L(-1) d(-1). The algae-treated wastewater was subsequently ozonated to comply with discharge permits that limit color in the effluent, which also resulted in improved biodegradability of residual organics. The integrated treatment scheme proposed in this study also achieved 89% removal of COD, 88% removal of TN, and 60% removal of TP. The advantage of using the hybrid configuration suggests that this would be a promising strategy in full-scale treatment facilities for piggery effluent.

Prognostic values of gray matter to white matter ratios on early brain computed tomography in adult comatose patients after out-of-hospital cardiac arrest of cardiac etiology.

AIM OF THE STUDY: Previous studies found that the gray matter to white matter ratio (GWR) on brain computed tomography (CT) could be used to predict poor outcomes in cardiac arrest survivors. However, these studies have included cardiac arrests of both cardiac and non-cardiac etiologies. We sought to evaluate if the GWR on brain CT can help to predict poor outcomes after out-of-hospital cardiac arrest (OHCA) of cardiac etiology. METHODS: Using a multicenter retrospective registry of adult cardiac arrest survivors treated with therapeutic hypothermia, we identified survivors of OHCA of cardiac etiology who underwent brain CT within 24h after successful resuscitation. Gray and white matter attenuations were measured, and the GWRs were calculated as in previous studies. The prognostic values of the GWRs were analyzed, and a logistic regression analysis was performed to determine the contribution of the GWR in predicting poor outcomes (Cerebral Performance Category 3-5). RESULTS: of 283 included patients, 140 had good outcomes and 143 had poor outcomes. Although the GWRs could predict poor outcomes with statistical significance, the sensitivities were remarkably low (3.5% to 5.6%) at cutoff values with 100% specificity. No significant difference in predictive performance was found between the primary predictive model, containing independent poor outcome predictors, and the primary predictive model combined with the GWR. CONCLUSION: In a cohort of comatose adults after OHCA of cardiac etiology, the GWR demonstrated poor predictive performance and was not helpful in predicting poor outcomes.

Patchable, flexible heat-sensing hybrid ionic gate nanochannel modified with a wax-composite.

Heat-driven ionic gate nanochannels have been recently demonstrated, which exploit temperature-responsive polymer brushes based on wettability. These heat-sensing artificial nanochannels operate in a broad temperature-response boundary and fixed liquid cell environment, thereby experiencing limited system operation in the flat and solid state. Here we have developed a patchable and flexible heat-sensing artificial ionic gate nanochannel, which can operate in the range of the human body temperature. A wax-elastic copolymer, coated onto a commercial nanopore membrane by a controlled-vacuum filtration method, was used for the construction of temperature-responsive nanopores. The robust and flexible nanochannel heat sensor, which is combined with an agarose gel electrolyte, can sustain reversible thermo-responsive ionic gating based on the volumetric work of the wax-composite layers in a selective temperature range. The ionic current is also effectively distinguished in the patchable bandage-type nanochannel for human heat-sensing.

Outcomes of asphyxial cardiac arrest patients who were treated with therapeutic hypothermia: a multicentre retrospective cohort study.

INTRODUCTION: While therapeutic hypothermia (TH) is in clinical use, its efficacy in certain patient groups is unclear. This study was designed to describe the characteristics and outcomes of patients with out-of-hospital cardiac-arrest (OHCA) caused by asphyxia, who were treated with TH. PATIENTS AND METHODS: A multicentre, retrospective, registry-based study was performed using data from the period 2007-2012. Comatose patients who were treated with TH after asphyxial cardiac arrest were included, while those who with cardiac arrest attributed to hanging, drowning or gas intoxication were excluded. RESULTS: Of a total of 932 OHCA patients in the registry, 111 were enrolled in this study. The mean age was 65.8±16.3 years with individuals who were ≥65 years of age accounted for 61.3% of the cohort. Foreign-body airway obstruction was the most common cause (70.3%) of the cardiac arrest. Eighty patients (72.1%) presented with an initial non-shockable rhythm. In all institutions target TH temperatures were 32-34°C, but TH maintenance times varied. A total of 52 patients (46.8%) survived, of whom six patients (5.4%) showed a good neurologic outcome (cerebral performance category scale 1-2). The pupil light reflex, corneal reflex and time to return of spontaneous circulation (p=0.012, 0.015 and 0.032, respectively) were associated with survival. Witnessed arrest, age, previous lung disease, bystander basic life support and time factors were not associated with survival. CONCLUSION: About half of patients who underwent TH after asphyxial cardiac arrest survived, but a very small number showed a good neurologic outcome. The TH maintenance times were not uniform in these patients. Additional research regarding both the appropriate TH guidelines for patients with asphyxial cardiac arrest and improvement of their neurologic outcome is needed.

A micro-fabricated force sensor using an all thin film piezoelectric active sensor.

The ability to measure pressure and force is essential in biomedical applications such as minimally invasive surgery (MIS) and palpation for detecting cancer cysts. Here, we report a force sensor for measuring a shear and normal force by combining an arrayed piezoelectric sensors layer with a precut glass top plate connected by four stress concentrating legs. We designed and fabricated a thin film piezoelectric force sensor and proposed an enhanced sensing tool to be used for analyzing gentle touches without the external voltage source used in FET sensors. Both the linear sensor response from 3 kPa to 30 kPa and the exact signal responses from the moving direction illustrate the strong feasibility of the described thin film miniaturized piezoelectric force sensor.

Outcome and current status of therapeutic hypothermia after out-of-hospital cardiac arrest in Korea using data from the Korea Hypothermia Network registry.

OBJECTIVE: Therapeutic hypothermia (TH) has become the standard strategy for reducing brain damage in the postresuscitation period. The aim of this study was to investigate current TH performance and outcomes in out-of-hospital cardiac arrest (OHCA) survivors using data from the Korean Hypothermia Network (KORHN) registry. METHODS: We used the KORHN registry, a web-based multicenter registry that includes 24 participating hospitals throughout the Republic of Korea. Adult comatose OHCA survivors treated with TH between 2007 and 2012 were included. The primary outcomes were neurological outcome at hospital discharge and in-hospital mortality. The secondary outcomes were TH performance and adverse events during TH. RESULTS: A total of 930 patients were included, of whom 556 (59.8%) survived to discharge and 249 (26.8%) were discharged with good neurologic outcomes. The median time from return of spontaneous circulation (ROSC) to the start of TH was 101 minutes (interquartile range [IQR], 46 to 200 minutes). The induction, maintenance, and rewarming durations were 150 minutes (IQR, 80 to 267 minutes), 1,440 minutes (IQR, 1,290 to 1,440 minutes), and 708 minutes (IQR, 420 to 900 minutes), respectively. The time from the ROSC to coronary angiography was 1,045 hours (IQR, 121 to 12,051 hours). Hyperglycemia (46.3%) was the most frequent adverse event. CONCLUSION: More than one-quarter of the OHCA survivors (26.8%) were discharged with good neurologic outcomes. TH performance was appropriately managed in terms of the factors related to its timing, including cooling start time and rewarming duration.

Optimizing cultivation strategies for robust algal growth and consequent removal of inorganic nutrients in pretreated livestock effluent.

Dilution was employed as a pretreatment strategy to increase light transmittance and decrease ammonia toxicity in piggery effluent prior to the cultivation of microalgae. The dilution effect was quantitatively determined based on both the maximum specific nutrient consumption rate and the maximum growth coefficient to minimize the usage of diluent. The biomass productivity of microalgae was also evaluated to select the best species among the five different candidates examined. A 20-fold dilution of piggery wastewater resulted in decreased chromaticity (584 mg Pt-Co L(-1)) and total nitrogen (76 mg L(-1)), on which the microalgae cultivation was more effective for an algal growth compared to the other dilution factors. If the initial cell concentration of Scenedesmus quadricauda increased, the production of biomass tended to improve. Robust growth and harvesting of S. quadricauda were achieved, and the associated consistent removal of inorganic nutrients was accomplished during the semi-continuous cultivation of the best species.