Temperature modulated sustainable on/off photosynthesis switching of microalgae towards hydrogen evolution.

Despite great progress in the active interfacing between various abiotic materials and living organisms, the development of a smart polymer matrix with modulated functionality of algae towards the application of green bioenergy is still rare. Herein, we design a thermally sensitive poly(N-isopropylacrylamide)-co-poly(butyl acrylate) with an LCST (ca. 25 °C) as a chassis, which could co-assemble with algal cells based on hydrophobic interaction to generate a new type of robust hybrid hydrogel living material. By modulating the temperature to 30 °C, the volume of the polymer matrix is shrunk by 9 times, which allows the formation of physical shading and metabolism changing of the algae, and then triggers the functionality switching of the algae from photosynthetic oxygen production to hydrogen production. By contrast, by decreasing the temperature to 20 °C, the hybrid living materials go into a sol state where the algae behave normally with photosynthetic oxygen production. In particular, due to the proliferation of the algae in living materials, a long-term and exponential enhancement in the amount of hydrogen produced is achieved. Overall, it is anticipated that our investigations could provide a new paradigm for the development of polymer/living organism-based hybrid living materials with synergistic functionality boosting green biomanufacturing.

The impact of chemical properties of the solid-liquid-adsorbate interfaces on the entropy-enthalpy compensation involved in adsorption.

Despite extensive studies on the thermodynamic mechanism governing molecular adsorption at the solid-water interface, a comprehensive understanding of the crucial role of interface properties in mediating the entropy-enthalpy compensation during adsorption is lacking, particularly at a quantitative level. Herein, we employed two types of surface models (hydroxyapatite and graphene) along with a series of amino acids to successfully elucidate how distinct interfacial features dictate the delicate balance between entropy and enthalpy variations. The adsorption of all amino acids on the hydroxyapatite surface is an enthalpy-dominated process, where the water-induced enthalpic component of the free energy and the surface-adsorbate electrostatic interaction term alternatively act as the driving force for adsorption in different regions of the surface. Although favorable interactions are observed between amino acids and the graphene surface, the entropy-enthalpy compensation exhibits dependence on the molecular size of the adsorbates. For small amino acids, favorable enthalpy changes predominantly determine their adsorption behavior; however, larger amino acids tend to bind more tightly with the graphene surface, which is thermodynamically dominated by the entropy variations despite the structural characteristics of amino acids. This study reveals specific entropy-enthalpy mechanisms underlying amino acid adsorption at the solid-liquid interface, providing guidance for surface design and synthesis of new biomolecules.

Utilizing nanotechnology to boost the reliability and determine the vertical load capacity of pile assemblies.

Because of their high electrocatalytic activity, sensitivity, selectivity, and long-term stability in electrochemical sensors and biosensors, numerous nanomaterials are being used as suitable electrode materials thanks to developments in nanotechnology. Electrochemical sensors and biosensors are two areas where two-dimensional layered materials (2DLMs) are finding increasing utility due to their unusual structure and physicochemical features. Nanosensors, by their unprecedented sensitivity and minute scale, can probe deeper into the structural integrity of piles, capturing intricacies that traditional tools overlook. These advanced devices detect anomalies, voids, and minute defects in the pile structure with unparalleled granularity. Their effectiveness lies in detection and their capacity to provide real-time feedback on pile health, heralding a shift from reactive to proactive maintenance methodologies. Harvesting data from these nanosensors, data was incorporated into a probabilistic model, executing the reliability index calculations through Monte Carlo simulations. Preliminary outcomes show a commendable enhancement in the predictability of vertical bearing capacity, with the coefficient of variation dwindling by up to 12%. The introduction of nanosensors facilitates instantaneous monitoring and fortifies the long-term stability of pile foundations. This study accentuates the transformative potential of nanosensors in geotechnical engineering.

Laparoscopic cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for gastric cancer with intraoperative detection of limited peritoneal metastasis: a Phase II study of CLASS-05 trial.

Background: Systemic chemotherapy for gastric cancer with peritoneal metastasis has limited clinical benefit; for those with intraoperative detection of occult peritoneal metastasis, cytoreductive surgery followed by hyperthermic intraperitoneal chemotherapy (HIPEC) is an alternative treatment. However, the feasibility and effects of this modality and criteria for selecting suitable groups remain unclear. This study aimed to explore the safety and efficacy of laparoscopic cytoreductive surgery (L-CRS) followed by HIPEC in gastric cancer with limited peritoneal metastasis, and this study also aimed to determine the optimized cut-off of the peritoneal cancer index. Methods: Between March 2017 and November 2019, patients diagnosed with gastric cancer peritoneal metastases by using laparoscopy and the Sugarbaker peritoneal cancer index of ≤12 were eligible for inclusion. All patients received L-CRS (including gastrectomy with D2 lymph node dissection) and resection of visible peritoneal metastasis, followed by post-operative HIPEC, and systemic chemotherapy. The primary end points were median progression-free survival and median survival time, and the secondary outcomes were morbidity and mortality within 30 days after surgery. Results: Thirty patients were eligible for analysis, of whom 19 (63.3%) were female, and the overall mean age was 53.0 years. The post-operative morbidity was 20% and the severe complication rate was 10%. The median survival time was 27.0 months with a 2-year overall survival rate of 52.3% and median progression-free survival was 14.0 months with a 2-year progression-free survival of 30.4%. Conclusions: L-CRS followed by HIPEC can be safely performed for gastric cancer with limited peritoneal metastasis and potential survival benefits.

Experimental study on the significance of pressure relief effect and crack extension law under uniaxial compression of rock-like materials containing drill holes.

The drilling pressure relief technology is an effective way to reduce the accumulation of elastic energy in the tunnel envelope, which can reduce the risk of regional ground pressure occurrence. However, there is a lack of theoretical guidance on which drilling parameter has the greatest degree of influence on the effectiveness of pressure relief. The uniaxial compression tests were conducted to study the relationships between drilling parameters (the diameter, depth, and spacing) and the mechanical properties and deformation modulus of specimens. The results show that: (1) The drilling diameter (DDR) and drilling depth (DDH) of single-hole specimens negatively correlate with the peak-failure strength and deformation modulus, while the drilling spacing (DS) of double-hole specimens positively correlates with the peak-failure strength and deformation modulus. It shows that the borehole diameter has a more significant effect on the decompression effect. (2) With the help of the Grey Relational Analysis, the factors affecting the peak-failure strength and deformation modulus of the drilled specimens were ranked in significance. From the largest to the smallest, they are DDR, followed by DDH and DS. (3) The role of the pressure relief mechanism is to transfer the high stress in the shallow part of the roadway to the deep part, reduce the peak strength of destruction and deformation modulus of the peripheral rock in the drilled section, so that the characteristics of the mechanical behavior of the rock are significantly weakened, and the range of the area of the drilled hole decompression is enlarged. During the loading of the borehole, the borehole stress field dominates in the early stage, and cracking starts near the borehole along the direction perpendicular to the direction of maximum principal stress (horizontal direction). In the later stage, the maximum principal stress field dominates and vertical cracks with large widths appear. During crack expansion, the plastic energy dissipation effect is enhanced and the deep impact conduction path is weakened, thus protecting the roadway. This study determined the significance of the pressure relief effect of different drilling parameters, which can guide reasonable modifications of drilling parameters in the field.

A dynamic nomogram for predicting 28-day mortality in septic shock: a Chinese retrospective cohort study.

Background: Septic shock is a severe life-threatening disease, and the mortality of septic shock in China was approximately 37.3% that lacks prognostic prediction model. This study aimed to develop and validate a prediction model to predict 28-day mortality for Chinese patients with septic shock. Methods: This retrospective cohort study enrolled patients from Intensive Care Unit (ICU) of the Second Affiliated Hospital, School of Medicine, Zhejiang University between December 2020 and September 2021. We collected patients' clinical data: demographic data and physical condition data on admission, laboratory data on admission and treatment method. Patients were randomly divided into training and testing sets in a ratio of 7:3. Univariate logistic regression was adopted to screen for potential predictors, and stepwise regression was further used to screen for predictors in the training set. Prediction model was constructed based on these predictors. A dynamic nomogram was performed based on the results of prediction model. Using receiver operator characteristic (ROC) curve to assess predicting performance of dynamic nomogram, which were compared with Sepsis Organ Failure Assessment (SOFA) and Acute Physiology and Chronic Health Evaluation II (APACHE II) systems. Results: A total of 304 patients with septic shock were included, with a 28-day mortality of 25.66%. Systolic blood pressure, cerebrovascular disease, Na, oxygenation index (PaO2/FiO2), prothrombin time, glucocorticoids, and hemodialysis were identified as predictors for 28-day mortality in septic shock patients, which were combined to construct the predictive model. A dynamic nomogram (https://zhijunxu.shinyapps.io/DynNomapp/) was developed. The dynamic nomogram model showed a good discrimination with area under the ROC curve of 0.829 in the training set and 0.825 in the testing set. Additionally, the study suggested that the dynamic nomogram has a good predictive value than SOFA and APACHE II. Conclusion: The dynamic nomogram for predicting 28-day mortality in Chinese patients with septic shock may help physicians to assess patient survival and optimize personalized treatment strategies for septic shock.

A case study on new high-strength temporary support technology of extremely soft coal seam roadway.

One of the main challenges in excavating roadways is implementing temporary supports that are powered by hydraulics and have high strength. The current temporary support system lacks active support and often causes separation between the top plate and the layer below. It is crucial to control the initial separation of the roadway roof for the stability of the surrounding rock, especially on roadways with loose and soft rock. This research focuses on the A4027 return airway in Sail Six Mine. The issues with the temporary support system in this airway have been identified. The concept and principle of using hydraulically driven, high-strength temporary support technology are proposed. A mechanical analysis model is created to study the stacked roof in the temporary support region, and the critical conditions for delamination of the top plate are determined. The relationship between the delamination difficulty parameter Q, the distance between temporary supports L, and the strength of the temporary supports q is quantified. Numerical simulation using Flac3d is used to model the relationship between the strength of the temporary supports and the deformation and stress of the rock on the roof. The overall strength of the temporary supports for the A4027 return airway is determined to be 10 kN/m2, with a distance of 2 m between the temporary supports. Hydraulically driven, high-strength temporary support devices are developed and tested for their strength. Field trials are conducted as well. The results show that the initial separation of the top plate is improved and that the support effect in the temporary support region is significant. The maximum separation of the top plate during excavation is only 34 mm, and the sinking of the top plate does not exceed 68 mm. This effectively limits the deformation of the surrounding rocks in the very soft coal seam, providing valuable insights for other roadways with similar conditions.

LncRNA AC125982.2 regulates apoptosis of cardiomyocytes through mir-450b-3p/ATG4B axis in a rat model with myocardial infarction.

Background: The occurrence and disability of myocardial infarction (MI) are on the rise globally, making it a significant contributor to cardiovascular mortality. Irreversible myocardial apoptosis plays a crucial role in causing MI. Long non-coding RNAs (LncRNAs) are key regulators of the cardiac remodeling process. Therefore, it is necessary to explore the effect of LncRNAs on cardiomyocyte apoptosis in MI. Methods: The rat-MI model was constructed, LncRNA-Seq and qPCR analyses were used to determine differentially expressed genes obtained from heart tissue of rats in the MI and sham groups. The miRanda software was used to predict the binding sites of LncRNA-miRNA and miRNA-mRNA, which were futhrer verified by dual luciferase assay. The LncRNA-miRNA-apoptosis pathway was further validated using hypoxia-exposed primary cardiomyocytes. Results: Compared to the sham group, 412 LncRNAs were upregulated and 501 LncRNAs were downregulated in MI-rat heart tissues. Among them, LncRNA AC125982.2 was most significantly upregulated in MI-rat heart tissues and hypoxic cardiomyocytes. Knockdown of AC125982.2 and ATG4B expression reversed hypoxia-induced apoptosis. In addition, transfection of mir-450b-3p inhibitor attenuated the protective effect of AC125982.2 knockdown. Moreover, we found that AC125982.2 modulated ATG4B expression by acting as a sponge for miR-450b-3p. Conclusion: Upregulated AC125982.2 expression regulates ATG4B by sponging miR-450b-3p, promoting cardiomyocyte apoptosis and contributing to rat MI development.

Knockdown of FOXRED2 restrains proliferation, invasion and migration of human melanoma cells.

Objectives: This experiment investigated the role of the FAD-dependent oxidoreductase domain-containing 2 (FOXRED2) in the development of cutaneous malignant melanoma. Methods: We explored the expression and prognostic effects of FOXRED2 in cutaneous malignant melanoma by performing bioinformatics analyses and immunohistochemical staining experiments and verified the biological influence of FOXRED2 on human melanoma cells using in vitro experiments. Results: FOXRED2 expression was significantly higher in cutaneous malignant melanoma compared to normal skin and nevus tissues and closely associated with prognosis. The expression levels of FOXRED2 mRNA and protein were significantly upregulated in human melanoma cell lines, and knocking down FOXRED2 expression inhibits proliferation, invasion, and migration, promotes apoptosis, and alters tumor cell biology in A2058 and A375 cells. Conclusion: FOXRED2 may play a crucial role in the development and progression of cutaneous malignant melanoma.

Influence of immunosuppressive drugs on natural killer cells in therapeutic drug exposure in liver transplantation.

Background: Natural killer (NK) cells are enriched in the liver and are the main regulators in liver transplantation regarding rejection or tolerance, viral infection, or tumor recurrence. Immunosuppression consists of a triple drug standard regimen comprising tacrolimus (TAC) and corticosteroids (CS) with either mycophenolate mofetil (MMF) or sirolimus (SIR)/everolimus (EVE). The aim of this study was to evaluate the impact of trough levels of these regimens under clinical conditions and exposure on human NK-cell activity and function in order to better understand the antiviral and anti-tumor effects of mammalian target of rapamycin inhibitor (mTORI). Methods: Peripheral blood mononuclear cells (PBMCs) were collected from liver transplant recipients and healthy controls. Number and phenotypes of NK cells in vivo were analyzed by flow cytometry. In this study we simulated the immunosuppressive microenvironment in vitro. PBMCs were cultured at the clinically effective plasma concentration of drugs for 3 d to detect the effect of immunosuppressants on NK cells. Drug type and concentration: single drug [EVE, 5 ng/mL; SIR, 5 ng/mL; TAC, 5 ng/mL; cyclosporine A (CSA), 125 ng/mL; MMF, 15 µg/mL; CS, 0.5 µg/mL] and combined immunosuppressants (Group 1: TAC, 5 ng/mL + MMF, 15 µg/mL + CS, 0.5 µg/mL; Group 2: TAC, 5 ng/mL + SIR, 5 ng/mL + CS, 0.5 µg/mL; Group 3: TAC, 5 ng/mL + EVE, 5 ng/mL + CS, 0.5 µg/mL). In addition, NK cells were sorted from PBMCs and treated under the above conditions to detect NK cell killing function and RNA transcription characteristics. Results: CS significantly impaired the cytolytic activity of NK cells, followed by MMF and SIR/EVE. CS and TAC/CSA significantly decreased the secretion of IFN-γ and CD107a. NK cell function in liver transplant recipients was most pronouncedly inhibited by a triple immunosuppressive regimen, with CS playing the most prominent role compared with the other drugs. The MMF-containing regimen demonstrated a significant increase in the expression of suppressive genes, especially of the Siglec7/9 family. The SIR group had stronger NK cell activity compared with that of the MMF group, although liver transplantation patients have lower NK cell activity and function. Conclusions: Despite an overall comparable immunosuppressive efficiency in terms of prevention of acute rejection, a mTORIs-including regimen might be considered as having less impact on NK cell function.

Research on dynamic response characteristics of normal fault footwall working face and rock burst prevention technology under the influence of the gob area.

To study the effect of mining dynamic response characteristics on the footwall working face of the normal fault under the influence of the gob area, theoretical research, indoor experiment, and numerical simulation are adopted to analyze the stress manifestation characteristics, overburden movement, and energy evolution characteristics during the process of mining. The results show that: (1) In the process of mining toward the fault, the working face shows the change characteristics of "stable-activation mutation-final stability". At 20 m from the fault, the arch structure of the working face was damaged, fissures appeared near the high fault fracture zone, and the displacement of the overburden rock increased significantly; (2) the maximum value was reached at 4-8 m from the coal wall, and the superposition of tectonic stress and mining stress led to the concentration of the stress and energy accumulating on the top plate near the fault, and the data close to the gob area were even larger; (3) If the plastic damage zone of the high-level rock layer on the hanging wall and footwall of the fault appears to have a wide range of penetration, and the area formed between the shear displacement curve of the fault plane and the X-axis appears to have a significant enhancement, it is considered that the fault has been activated; (4) The size of the coal pillar of the fault is determined to be 40 m, and combined with the pressure unloading technique of the variable-diameter drilling hole, the validation is carried out through the micro-vibration monitoring, and the results of which can be used as a reference for the safety of the working face under similar conditions.

Catalytic metal-nucleotide coordinative cytoskeleton on algae cell towards photosynthetic hydrogen production under air.

A metal-nucleotide coordinative cytoskeleton with ascorbate oxidase-like catalytic behavior was constructed on an individual algae cell wall, which endows the engineered cells with the capability of self-generating a localized hypoxic microenvironment around the cell surface, and thus allows the functionality switching from photosynthetic oxygen production to efficient hydrogen evolution for over one month.

Lanosterol synthase loss of function decreases the malignant phenotypes of HepG2 cells by deactivating the Src/MAPK signaling pathway.

Cholesterol is critical for tumor cells to maintain their membrane components, cell morphology and activity functions. The inhibition of the cholesterol pathway may be an efficient strategy with which to limit tumor growth and the metastatic process. In the present study, lanosterol synthase (LSS) was knocked down by transfecting LSS short hairpin RNA into HepG2 cells, and cell growth, apoptosis and migratory potential were then detected by Cell Counting Kit-8 cell proliferation assay, flow cytometric analysis and wound healing assay, respectively. In addition, proteins associated with the regulation of the aforementioned cell biological behaviors were analyzed by western blot analysis. The activity of the Src/MAPK signaling pathway was measured by western blotting to elucidate the possible signal transduction mechanisms. LSS knockdown in the HepG2 liver cancer cell line inhibited cell proliferation, with cell cycle arrest at the S phase; it also decreased cell migratory ability and increased apoptosis. The expression proteins involved in the regulation of cell cycle, cell apoptosis and migration was altered by LSS knockdown in HepG2 cells. Furthermore, a decreased Src/MAPK activity was observed in the HepG2 cells subjected to LSS knockdown. LSS loss of function decreased the malignant phenotypes of HepG2 cells by deactivating the Src/MAPK signaling pathway and regulating expression of genes involved in cell cycle regulation, cell apoptosis and migration.

Tyrosine residues initiated photopolymerization in living organisms.

Towards intracellular engineering of living organisms, the development of new biocompatible polymerization system applicable for an intrinsically non-natural macromolecules synthesis for modulating living organism function/behavior is a key step. Herein, we find that the tyrosine residues in the cofactor-free proteins can be employed to mediate controlled radical polymerization under 405 nm light. A proton-coupled electron transfer (PCET) mechanism between the excited-state TyrOH* residue in proteins and the monomer or the chain transfer agent is confirmed. By using Tyr-containing proteins, a wide range of well-defined polymers are successfully generated. Especially, the developed photopolymerization system shows good biocompatibility, which can achieve in-situ extracellular polymerization from the surface of yeast cells for agglutination/anti-agglutination functional manipulation or intracellular polymerization inside yeast cells, respectively. Besides providing a universal aqueous photopolymerization system, this study should contribute a new way to generate various non-natural polymers in vitro or in vivo to engineer living organism functions and behaviours.

Photosynthesis-Mediated Intracellular Biomineralization of Gold Nanoparticles inside Chlorella Cells towards Hydrogen Boosting under Green Light.

Engineering living microorganisms to enhance green biomanufacturing for the development of sustainable and carbon-neutral energy strategies has attracted the interest of researchers from a wide range of scientific communities. In this study, we develop a method to achieve photosynthesis-mediated biomineralization of gold nanoparticles (AuNPs) inside Chlorella cells, where the photosynthesis-dominated reduction of Au3+ to Au0 allows the formed AuNPs to locate preferentially around the thylakoid membrane domain. In particular, we reveal that the electrons generated by the localized surface plasmon resonance of AuNPs could greatly augment hypoxic photosynthesis, which then promotes the generation and transferring of photoelectrons throughout the photosynthetic chain for augmented hydrogen production under sunlight. We demonstrate that the electrons from AuNPs could be directly transferred to hydrogenase, giving rise to an 8.3-fold enhancement of Chlorella cells hydrogen production independent of the cellular photosynthetic process under monochromatic 560 nm light irradiation. Overall, the photosynthesis-mediated intracellular biomineralization of AuNPs could contribute to a novel paradigm for functionalizing Chlorella cells to augment biomanufacturing.

Algal cell bionics as a step towards photosynthesis-independent hydrogen production.

The engineering and modulation of living micro-organisms is a key challenge in green bio-manufacturing for the development of sustainable and carbon-neutral energy technologies. Here, we develop a cellular bionic approach in which living algal cells are interfaced with an ultra-thin shell of a conductive polymer along with a calcium carbonate exoskeleton to produce a discrete cellular micro-niche capable of sustained photosynthetic and photosynthetic-independent hydrogen production. The surface-augmented algal cells induce oxygen depletion, conduct photo-induced extracellular electrons, and provide structural and chemical stability that collectively give rise to localized hypoxic conditions and concomitant hydrogenase activity under daylight in air. We show that assembly of the living cellular micro-niche opens a direct extracellular photoelectron pathway to hydrogenase resulting in photosynthesis-independent hydrogen evolution for 200 d. In addition, surface-conductive dead algal cells continue to produce hydrogen for up to 8 d due to their structural stability and retention of functional hydrogenases. Overall, the integration of artificial biological hydrogen production pathways and natural photosynthesis in surface-augmented algal cells provides a cellular bionic approach to enhanced green hydrogen production under environmentally benign conditions and could pave the way to new opportunities in sustainable energy production.

Entecavir Combined With Short-term Hepatitis B Immunoglobulin in Preventing Hepatitis B Virus Recurrence in Liver Transplant Recipients.

BACKGROUND: The combination of nucleoside analogs and long-term hepatitis B immunoglobulin (HBIG) is considered to be the standard regimen for preventing hepatitis B virus (HBV) recurrence after liver transplant (LT). However, long-term use of HBIG causes many adverse effects. The aim of this study was to evaluate the effect of nucleoside analogs entecavir combined with short-term HBIG in preventing HBV recurrence after LT. METHODS: This retrospective study assessed the effect a combination of entecavir and short-term HBIG in prophylaxis of HBV recurrence among 56 LT recipients who had undergone the procedure because of HBV-associated liver disease at our center between December 2017 and December 2021. All patients received entecavir treatment combined with HBIG for the prevention of hepatitis B recurrence, and HBIG treatment was withdrawn within 1 month. The patients were followed up to determine levels of hepatitis B surface antigen, antibody to hepatitis B surface antigen (HBsAb), and HBV-DNA and the recurrence rate of HBV. RESULTS: Only 1 patient appeared positive for hepatitis B surface antigen at 2 months post-LT. The overall HBV recurrence rate was 1.8%. The HBsAb titers of all patients gradually decreased over time, with a median of 376.6 IU/L at 1 month post-LT and a median of 13.47 IU/L at 12 months post-LT. During the follow-up period, the HBsAb titer of the preoperative HBV-DNA-positive patients remained at a lower level than that of HBV-DNA-negative patients. CONCLUSIONS: Entecavir combined with short-term HBIG can exert a good effect for the prevention of HBV reinfection post-LT.

Simulation of Photosynthetic Quantum Efficiency and Energy Distribution Analysis Reveals Differential Drought Response Strategies in Two (Drought-Resistant and -Susceptible) Sugarcane Cultivars.

Selections of drought-tolerant cultivars and drought-stress diagnosis are important for sugarcane production under seasonal drought, which becomes a crucial factor causing sugarcane yield reduction. The main objective of this study was to investigate the differential drought-response strategies of drought-resistant ('ROC22') and -susceptible ('ROC16') sugarcane cultivars via photosynthetic quantum efficiency (Φ) simulation and analyze photosystem energy distribution. Five experiments were conducted to measure chlorophyll fluorescence parameters under different photothermal and natural drought conditions. The response model of Φ to photosynthetically active radiation (PAR), temperature (T), and the relative water content of the substrate (rSWC) was established for both cultivars. The results showed that the decreasing rate of Φ was higher at lower temperatures than at higher temperatures, with increasing PAR under well-watered conditions. The drought-stress indexes (εD) of both cultivars increased after rSWC decreased to the critical values of 40% and 29% for 'ROC22' and 'ROC16', respectively, indicating that the photosystem of 'ROC22' reacted more quickly than that of 'ROC16' to water deficit. An earlier response and higher capability of nonphotochemical quenching (NPQ) accompanied the slower and slighter increments of the yield for other energy losses (ΦNO) for 'ROC22' (at day5, with a rSWC of 40%) compared with 'ROC16' (at day3, with a rSWC of 56%), indicating that a rapid decrease in water consumption and an increase in energy dissipation involved in delaying the photosystem injury could contribute to drought tolerance for sugarcane. In addition, the rSWC of 'ROC16' was lower than that of 'ROC22' throughout the drought treatment, suggesting that high water consumption might be adverse to drought tolerance of sugarcane. This model could be applied for drought-tolerance assessment or drought-stress diagnosis for sugarcane cultivars.