Nutritional support therapy for liver transplantation in an adult-onset type II citrullinemia patient: a case report.

Liver transplantation is an effective measure to treat adult-onset type II citrullinemia (CTLN2). Active and effective perioperative nutrition support is a very important treatment for the prognosis of such patients. In this paper, we analyzed the process, results, and outcome of nutritional support therapy in a case of CTLN2, and concluded that the perioperative nutritional support program for CTLN2 patients should be followed prior to surgery:1.because of the prevalence of severe malnutrition in CTLN2 patients, Enteral nutrition (EN) combined with Parenteral nutrition (PN) should be the first choice for nutritional support; 2. daily energy intake should be 35 ~ 40 kcal/kg; 3. the nutritional formula should be composed of low-carbohydrates and high medium-chain triglyceride (MCT). Postoperative: initiating EN as soon as possible is recommended to restore intestinal function and adjuvant PN might be taken into consideration in the early stage. The purpose of this case was to provide experience for the development and adjustment of the perioperative nutritional support regimen for CTLN2 patients.

The effects of manual therapy in pain and safety of patients with knee osteoarthritis: a systematic review and meta-analysis.

BACKGROUND: Manual therapy (MT) is frequently used in combination with management of osteoarthritis of the knee, but there is no consensus on the exact efficacy of this treatment strategy. The purpose of this systematic review and meta-analysis was to evaluate the pain relief and safety of MT for treatment of knee osteoarthritis (KOA). METHODS: Randomized controlled trials evaluating MT in patients with KOA in major English and Chinese journals were searched in the following databases: Wanfang, China Science and Technology Journal Database (VIP database), China National Knowledge Infrastructure (CNKI), PubMed, Embase, Web of Science, and the Cochrane Library databases through June 2023. The methodological quality and quality of evidence of the included studies were assessed using Cochrane's risk-of-bias 2 (ROB 2) tool and the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) tool. Data analysis was performed using Stata version 15.0 software. After use of Galbraith plots to exclude studies that could lead to heterogeneity, random effects models were used to analyze the remaining data and test the consistency of the findings. We used meta-regression to assess the effect of treatment period, patient age, and sex ratio on outcomes. Funnel plots and Egger's test were used to evaluate publication bias. Sensitivity analyses were used to determine the reliability of the results. RESULTS: A total of 25 studies, with 2376 participants, were included in this review. The overall methodological quality of the included studies was limited. Our findings suggest that MT has a positive impact on pain relief outcomes in KOA patients. The meta-analysis showed that MT was superior to usual care (SMD = 2.04, 95% CI 0.94, 3.14, I 2 = 96.3%; low evidence quality) and exercise (SMD = 1.56, 95% CI 0.41, 2.71, I 2 = 96.3%; low evidence quality) for reducing pain. In terms of improvement in visual analogue scale (VAS) scores, MT treatment beyond 4 weeks (SMD = 1.56, 95% CI 0.41, 2.71, I 2 = 96.3%) may be superior to treatments less than or equal to 4 weeks (SMD = 1.24, 95% CI 0.56, 1.95, I 2 = 94.7%). No serious adverse events associated with MT were reported. CONCLUSIONS: MT may be effective at reducing pain in patients with KOA and may be more effective after a 4-week treatment period. Compared with usual care and exercise therapy, MT may be superior at reducing KOA pain in the short term (9 weeks), but its long-term efficacy requires careful consideration of evidence-based outcomes. MT appears to be safe for KOA patients, though clinicians should inform patients of the potential risk of MT-related adverse events.

A novel predictor of unsustained return of spontaneous circulation in cardiac arrest patients through a combination of capnography and pulse oximetry: a multicenter observational study.

BACKGROUND: Unsustained return of spontaneous circulation (ROSC) is a critical barrier to survival in cardiac arrest patients. This study examined whether end-tidal carbon dioxide (ETCO2) and pulse oximetry photoplethysmogram (POP) parameters can be used to identify unsustained ROSC. METHODS: We conducted a multicenter observational prospective cohort study of consecutive patients with cardiac arrest from 2013 to 2014. Patients' general information, ETCO2, and POP parameters were collected and statistically analyzed. RESULTS: The included 105 ROSC episodes (from 80 cardiac arrest patients) comprised 51 sustained ROSC episodes and 54 unsustained ROSC episodes. The 24-hour survival rate was significantly higher in the sustained ROSC group than in the unsustained ROSC group (29.2% vs. 9.4%, P<0.05). The logistic regression analysis showed that the difference between after and before ROSC in ETCO2 (ΔETCO2) and the difference between after and before ROCS in area under the curve of POP (ΔAUCp) were independently associated with sustained ROSC (odds ratio [OR]=0.931, 95% confidence interval [95% CI] 0.881-0.984, P=0.011 and OR=0.998, 95% CI 0.997-0.999, P<0.001). The area under the receiver operating characteristic curve of ΔETCO2, ΔAUCp, and the combination of both to predict unsustained ROSC were 0.752 (95% CI 0.660-0.844), 0.883 (95% CI 0.818-0.948), and 0.902 (95% CI 0.842-0.962), respectively. CONCLUSION: Patients with unsustained ROSC have a poor prognosis. The combination of ΔETCO2 and ΔAUCp showed significant predictive value for unsustained ROSC.

Overlapping speckle correlation algorithm for high-resolution imaging and tracking of objects in unknown scattering media.

Optical imaging in scattering media is important to many fields but remains challenging. Recent methods have focused on imaging through thin scattering layers or thicker scattering media with prior knowledge of the sample, but this still limits practical applications. Here, we report an imaging method named 'speckle kinetography' that enables high-resolution imaging in unknown scattering media with thicknesses up to about 6 transport mean free paths. Speckle kinetography non-invasively records a series of incoherent speckle images accompanied by object motion and the inherently retained object information is extracted through an overlapping speckle correlation algorithm to construct the object's autocorrelation for imaging. Under single-colour light-emitting diode, white light, and fluorescence illumination, we experimentally demonstrate 1 µm resolution imaging and tracking of objects moving in scattering samples, while reducing the requirements for prior knowledge. We anticipate this method will enable imaging in currently inaccessible scenarios.

Maximum helical dichroism enabled by an exceptional point in non-Hermitian gradient metasurfaces.

Helical dichroism (HD) utilizing unbounded orbital angular momentum degree of freedom, has provided an important means of exploring chiral effects in diverse wave systems, surpassing the two-state constraint in circular dichroism that relies on intrinsic spin. However, the naturally feeble chiral signals that arise during wave-matter interactions pose significant challenges to the effective enlargement of HD. Here, we introduce a new paradigm for realizing maximum HD through non-Hermitian gradient metasurfaces by engineering a chiral exceptional point (EP) in intrinsic topological charge. The non-Hermitian gradient metasurfaces are empowered by the asymmetric coupling feature at the EP, enabling flexible construction to realize versatile chirality control in extreme circumstances where one chiral vortex is totally reflected and the opposite counterpart is completely absorbed or transmitted into the customized vortex modes. As the manifestation of the maximum HD, we present the first experimental demonstration of perfect chirality-selected vortex transmission in acoustics. Our findings open new venues to achieve maximum chirality and explore chiral physics of wave-matter interactions, which can boost many vortical applications in asymmetric chirality manipulation, one-way propagation, and information multiplexing.

A twenty-year dataset of high-resolution maize distribution in China.

China is the world's second-largest maize producer, contributing 23% to global production and playing a crucial role in stabilizing the global maize supply. Therefore, accurately mapping the maize distribution in China is of great significance for regional and global food security and international cereals trade. However, it still lacks a long-term maize distribution dataset with fine spatial resolution, because the existing high spatial resolution satellite datasets suffer from data gaps caused by cloud cover, especially in humid and cloudy regions. This study aimed to produce a long-term, high-resolution maize distribution map for China (China Crop Dataset-Maize, CCD-Maize) identifying maize in 22 provinces and municipalities from 2001 to 2020. The map was produced using a high spatiotemporal resolution fused dataset and a phenology-based method called Time-Weighted Dynamic Time Warping. A validation based on 54,281 field survey samples with a 30-m resolution showed that the average user's accuracy and producer's accuracy of CCD-Maize were 77.32% and 80.98%, respectively, and the overall accuracy was 80.06% over all 22 provinces.

Geometric Phase in Twisted Topological Complementary Pair.

Geometric phase enabled by spin-orbit coupling has attracted enormous interest in optics over the past few decades. However, it is only applicable to circularly-polarized light and encounters substantial challenges when applied to wave fields lacking the intrinsic spin degree of freedom. Here, a new paradigm is presented for achieving geometric phase by elucidating the concept of topological complementary pair (TCP), which arises from the combination of two compact phase elements possessing opposite intrinsic topological charge. Twisting the TCP leads to the generation of a linearly-varying geometric phase of arbitrary order, which is quantified by the intrinsic topological charge. Notably distinct from the conventional spin-orbit coupling-based theories, the proposed geometric phase is the direct result of the cyclic evolution of orbital-angular-momentum transformation in mode space, thereby exhibiting universality across classical wave systems. As a proof of concept, the existence of this geometric phase is experimentally demonstrated using scalar acoustic waves, showcasing the remarkable ability in the precise manipulation of acoustic waves at subwavelength scales. These findings engender a fresh understanding of wave-matter interaction in compact structures and establish a promising platform for exploring geometric phase, offering significant opportunities for diverse applications in wave systems.

Diagnosis and Treatment of Double Thyroglossal Duct Cyst.

This retrospective study aimed to investigate clinical diagnostic and management characteristics of double thyroglossal duct cyst (TDC) cases. Seventy-eight patients diagnosed with TDCs who were admitted to the inpatient ward of the Department of Otolaryngology, Dalian Central Municipal Hospital from June 2008 to October 2021 were included in the study. Ultimately, 67 of these patients were diagnosed with single TDCs and 11 patients with double TDCs. Each patient underwent computed tomography and color doppler ultrasound imaging of their neck masses, thyroid color doppler ultrasound imaging, and surgical cyst removal through the classic Sistrunk procedure. All surgically excised specimens were sent to the pathology lab for examination and were confirmed to contain TDCs. Two of the 67 patients with single TDCs experienced postoperative complications related to infections within the operative area, whereas no patients with double TDCs experienced postoperative infection, excessive bleeding, or other surgical complications. All cases were followed up for 1 to 3 years after surgery with no cyst recurrence observed. Double TDCs may present on physical examination as unilateral neck masses that interfere with tongue extension and movement and swallowing that can be identified using imaging methods. Correct clinical diagnosis and complete surgical removal of cysts are key measures for ensuring successful treatment outcomes for patients with TDCs.

A Systematic Review and Meta-analysis of SNOT-22 Outcomes After Sinus Surgery.

Background: All stakeholders in the healthcare system have prioritized and will continue to prioritize enhancing care quality. The measurement of sinus-specific quality of life (QOL) is potentially the most commonly used QOL parameter for chronic rhinosinusitis (CRS). Objective: A systematic review and meta-analysis were used in this study to determine the mean change in patients' scores on the 22-item Sino-Nasal Outcome Test (SNOT-22) before and after endoscopic sinus surgery (ESS) for CRS. Methods: PubMed, Google Scholar, and ScienceDirect were searched for articles that compared SNOT-22 scores before and after ESS in adult patients with CRS and were published between January 2000 and March 2023. The mean post-op change, 95% confidence interval (CI), forest plot, and inverse variance weighting were all generated using a random effects model. A mixed-effects meta-regression was used to analyze the effect of patient-specific characteristics across studies. Results: Fifteen prospective patient cohorts published from 2009 to 2023 were included in this meta-analysis. At an average follow-up of 25.5 months, all studies demonstrated a statistically significant difference in mean SNOT-22 scores between baseline and post-op time periods (P < .05), ranging from 5.1 to 55.4. Across all studies, the mean SNOT-22 changed significantly by 26.02 (95% CI: 12.83-38.60). According to a stepwise multivariate analysis, studies with higher mean age and mean pre-op SNOT-22 scores had greater changes in SNOT-22 scores following ESS, whereas trials with longer mean follow-up duration had smaller changes in SNOT-22 scores. Conclusion: Research utilizing the SNOT-22 instrument has demonstrated that endoscopic sinus surgery (ESS) leads to enhanced quality of life (QOL) outcomes. The literature reports that improvement is influenced by the initial SNOT-22 score, the mean age of the patients, and the duration of the follow-up period.

The Sino-Nasal Outcome Test-22 (SNOT-22) has shown that the quality-of-life results of sinus surgery after endoscopic sinus surgery (ESS) improve significantly. The amount of change seems to vary a lot from one study to the next, and this difference seems to be caused by things like the pre-op SNOT-22 score, the average age of the subjects, and the length of the tracking period. The results of this study give both a single number value and a range of changes that are likely to happen after surgery. These results can be used to guide projects that aim to improve the quality of care. Also, giving the Sino-Nasal Outcome Test-22 (SNOT-22) to people with chronic rhinosinusitis (CRS) before they have surgery may help them understand what effects they can expect, although this is up to each person to decide. Recent preliminary research shows that using SNOT-22 scores and tissue histopathology together could be a new way to predict how well treatment will work for people with CRS. The accuracy and precision of future analyses are likely to get better as efforts are made to get unbiased data and patient-level metrics from a wide range of patients and doctors.

Controlling the directional excitation of surface plasmon polaritons using tunable non-Hermitian metasurfaces.

In this work, we propose an efficient approach to controlling the directional excitation of surface plasmon polaritons (SPPs) by dynamically modulating the real-part perturbation in a passive parity-time symmetric metasurface. This non-Hermitian system can experience two exceptional points that can induce two unidirectional excitation states of SPPs along opposite directions. Empowered by its superior modulation depth, the energy ratio and energy intensities of two excited SPP states can be effectively manipulated by this non-Hermitian metasurface. To demonstrate these findings, we design and numerically verify non-Hermitian metasurfaces integrated with an Sb2Se3 phase-change material. Our work provides a promising platform for the controllable engineering of SPP excitations, holding significant potential for the development of new plasmonic devices, including on-chip SPP sources, routers and sorters, and integrated optical circuits.

Unidirectional manipulation of Smith-Purcell radiation by phase-gradient metasurfaces.

Here, we present a new, to the best of our knowledge, approach to control Smith-Purcell radiation (SPR) via phase-gradient metasurfaces (PGMs), i.e., periodic grating structures with gradient phase modulation. We show that the phase gradient and the parity design of the PGM can efficiently manipulate higher order diffraction to achieve perfect unidirectional SPR, which significantly alters the SPR in the spectrum and the spatial distribution beyond traditional understanding. Specifically, the even-parity PGM results in incidence-free unidirectional radiation, while the odd-parity PGM enables incidence-locking unidirectional radiation. This unidirectional SPR is very robust, ensured by the parity-dependent diffraction rule in PGMs. A modified formula is presented to reveal the relationship between the radiation wavelength and the radiation angle. Our findings offer a new way to control the electromagnetic radiation of moving charged particles (CPs) with structured materials, which may lead to novel applications in tunable, efficient light sources and particle detectors.

Switchable supermode emission in a doubly-coupled-ring system for multifunctional integrated photonic devices.

Effective integration of optical modes within chip-scale devices is critical to realize functional light emission, as it offers abundant physics and a versatile ability to control the mode evolution. Here, we present an efficient approach to achieve switchable emission by flexibly controlling supermode states in a doubly-coupled-ring system with four guided modes. The lasing conditions, which rely on the system's Hamiltonian, are revealed to yield multiple supermode states, including an exceptional-point state, a (quasi-)dark state, and a bright state. By freely engineering the coupling rate via phase-change material, the proposed system allows the generation of any desired states, enabling switchable and multifunctional emissions in fixed on-chip structures. Beyond the manipulation of various supermode emission states, our work presents a promising path toward the development of multifunctional integrated photonic devices, which may have applications in light storage, optical isolation, sensing, and so on.

Global, regional, and national burden of chronic respiratory diseases and associated risk factors, 1990-2019: Results from the Global Burden of Disease Study 2019.

Background: The burden of chronic respiratory diseases has changed over the three decades. This study aims to describe the spatiotemporal trends of prevalence, mortality, and disability-adjusted life years (DALY) due to chronic respiratory diseases (CRDs) worldwide during 1990-2019 using data from the Global Burden of Disease Study 2019 (GBD 2019). Methods: The prevalence, mortality, and DALY attributable to CRDs and risk factors from 1990 to 2019 were estimated. We also assessed the driving factors and potentiality for improvement with decomposition and frontier analyses, respectively. Results: In 2019, 454.56 [95% uncertainty interval (UI): 417.35-499.14] million individuals worldwide had a CRD, showing a 39·8% increase compared with 1990. Deaths due to CRDs were 3.97 (95%UI: 3.58-4.30) million, and DALY in 2019 was 103.53 (95%UI: 94.79-112.27) million. Declines by average annual percent change (AAPC) were observed in age-standardized prevalence rates (ASPR) (0.64% decrease), age-standardized mortality rates (ASMR) (1.92%), and age-standardized DALY rates (ASDR) (1.72%) globally and in 5 socio-demographic index (SDI) regions. Decomposition analyses represented that the increase in overall CRDs DALY was driven by aging and population growth. However, chronic obstructive pulmonary disease (COPD) was the leading driver of increased DALY worldwide. Frontier analyses witnessed significant improvement opportunities at all levels of the development spectrum. Smoking remained a leading risk factor (RF) for mortality and DALY, although it showed a downward trend. Air pollution, a growing factor especially in relatively low SDI regions, deserves our attention. Conclusion: Our study clarified that CRDs remain the leading causes of prevalence, mortality, and DALY worldwide, with growth in absolute numbers but declines in several age-standardized estimators since 1990. The estimated contribution of risk factors to mortality and DALY demands the need for urgent measures to improve them. Systematic review registration: http://ghdx.healthdata.org/gbd-results-tool.

[Treatment and factors associated with prognosis of hyperkalemia in the emergency department].

OBJECTIVE: To survey treatment and prognosis of hyperkalemia patients in the emergency department and to analyze factors associated with all-cause in-hospital mortality. METHODS: We implemented electronic hospital information system, extracted demographic characteristics, underlying diseases, laboratory findings, potassium lowering therapy and prognosis of hyperkalemia patients [age ≥ 18 years, serum potassium (K+) concentration ≥ 5.5 mmol/L] in the emergency department of Peking Union hospital in Beijing between June 1st 2019 to May 31st 2020. The enrolled subjects were divided into the non-survival group and the survival group according to their prognosis. Univariate analysis and Cox regression model were adopted to analyze factors affecting all-cause in-hospital mortality of hyperkalemia patients. RESULTS: A total of 579 patients [median age 64 (22) years; 310 men (53.5%) and 269 women (46.5%)] with hyperkalemia were enrolled, among which, 317 (54.7%), 143 (24.7%) and 119 (20.6%) were mild, moderate, and severe hyperkalemia, respectively. 499 (86.20%) patients received potassium-lowering therapy, forty-four treatment regimens were administered. Insulin and glucose (I+G, 61.3%), diuretics (Diu, 57.2%), sodium bicarbonate (SB, 41.9%) and calcium gluconate/chloride (CA, 44.4%) were commonly used for the treatment of hyperkalemiain the emergency department. The combination of insulin and glucose, calcium gluconate/chloride, diuretics and sodium bicarbonate (I+G+CA+Diu+SB) was the most favored combined treatment regimen of hyperkalemia in the emergency department. The higher serum potassium concentration, the higher proportion of administrating combined treatment regimen and/or hemodialysis (HD) (the proportion of administrating combined treatment regimen in mild, moderate, and severe hyperkalemia patients were 58.4%, 82.5% and 94.8%; the proportion of administrating HD in mild, moderate, and severe hyperkalemia patients were 9.7%, 13.3% and 16.0%, respectively). The proportion of achievement of normokalaemia elevated as the kinds of potassium lowering treatment included in the combined treatment regimen increased. The proportion of achievement of normokalaemia was 100% in the combined treatment regimen including 6 kinds of potassium lowering therapy. Among various potassium lowering treatments, HD contributed to the highest rate of achievement of normokalaemia (93.8%). 111 of 579 (19.20%) hyperkalemia patients died in hospital. Cox regression model revealed that complicated with cardiac dysfunction predicted higher mortality [hazard ratio (HR) = 1.757, 95% confidence interval (95%CI) was 1.155-2.672, P = 0.009]. Achievement of normokalaemia and administration of diuretics attributed to lower mortality (HR = 0.248, 95%CI was 0.155-0.398, P = 0.000; HR = 0.335, 95%CI was 0.211-0.531, P = 0.000, respectively). CONCLUSIONS: Treatment of hyperkalemia in the emergency department were various. Complicated with cardiac dysfunction were associated with higher mortality. Achieving normokalaemia was associated with decreased mortality.

Tunable dual quasi-bound states in continuum and electromagnetically induced transparency enabled by the broken material symmetry in all-dielectric compound gratings.

Dual quasi-bound states in continuum (quasi-BICs) enabled by the broken geometric symmetry offer an effective way to design high-quality photonic devices, yet challenged by tunable functionalities. Here we employ the material asymmetry originating from the tunable material property of phase-change materials to design quasi-BICs in all-dielectric compound gratings. We find the even and odd quasi-BICs are modulated by the geometric and material asymmetries, respectively, and this effect is ensured by two different types of structural symmetries in the compound structure. Particularly, tunable electromagnetically induced transparency (EIT) can be achieved by modulating the material asymmetry. Furthermore, we systematically design the compound gratings consisting of the phase-change material of Sb2Se3 to demonstrate tunable dual quasi-BICs and EITs. Analytical calculations and numerical simulations are performed to verify these findings. Our work provides a promising way to enhance the flexibility of realizing quasi-BICs, which may boost tunable applications in nanodevices assisted by quasi-BICs.

NETosis is critical in patients with severe community-acquired pneumonia.

Pneumonia is the fourth leading cause of death globally, and the reason for the high mortality rate of patients with severe community-acquired pneumonia (SCAP) remains elusive. Corticosteroid treatment reduces mortality in adults with SCAP but can cause numerous adverse events. Therefore, novel therapeutic targets need to be explored and new adjunctive immune drugs are urgently required. We analyzed the transcriptome data of peripheral blood leukocytes from patients with SCAP and healthy controls from three perspectives: differentially expressed genes, predicted functions of differentially expressed long non-coding RNAs, and transcriptional read-through. We discovered that the NETosis pathway was top-ranked in patients with SCAP caused by diverse kinds of pathogens. This provides a potential therapeutic strategy for treating patients. Furthermore, we calculated the correlation between the expression of genes involved in NETosis and the ratio of arterial oxygen partial pressure to fractional inspired oxygen. We identified four novel potential therapeutic targets for NETosis in patients with SCAP, including H4C15, H3-5, DNASE1, and PRKCB. In addition, a higher occurrence of transcriptional read-through is associated with a worse outcome in patients with SCAP, which probably can explain the high mortality rate of patients with SCAP.

Isolation of oligostilbenes from Iris lactea Pall. var. chinensis (Fisch.) Koidz and their anti-inflammatory activities.

Iris lactea Pall. var. chinensis (Fisch.) Koidz (Iris lactea) is an herbaceous perennial widely distributed in China, India, and South Korea. Iris lactea has been extensively used in traditional Chinese medicine. The present study isolated a new oligostilbene (compound 1), together with three known oligostilbenes (compounds 2, 3 and 4) from the seeds of Iris lactea. The structures of these compounds were elucidated by HRESIMS, NMR, and chemical analyses. The network-based pharmacologic analysis platform was used to predict the target proteins related to inflammation of isolated compounds. Furthermore, the isolated compounds were tested for their anti-inflammatory effects in LPS-stimulated RAW 264.7 cells. In this network, 138 candidate targets of compounds related to its therapeutic effect on inflammation were identified. In addition, compounds 1, 2, 3 and 4 significantly decreased NO content and the IL-6 levels as well as the expression of COX-2 in LPS-stimulated RAW 264.7 cells.

Reconfigurable chiral exceptional point and tunable non-reciprocity in a non-Hermitian system with phase-change material.

Non-Hermitian optics has emerged as a feasible and versatile platform to explore many extraordinary wave phenomena and novel applications. However, owing to ineluctable systematic errors, the constructed non-Hermitian phenomena could be easily broken, thus leading to a compromising performance in practice. Here we theoretically proposed a dynamically tunable mechanism through GST-based phase-change material (PCM) to achieve a reconfigurable non-Hermitian system, which is robust to access the chiral exceptional point (EP). Assisted by PCM that provides tunable coupling efficiency, the effective Hamiltonian of the studied doubly-coupled-ring-based non-Hermitian system can be effectively modulated to resist the external perturbations, thus enabling the reconfigurable chiral EP and a tunable non-reciprocal transmission. Moreover, such tunable properties are nonvolatile and require no static power consumption. With these superior performances, our findings pave a promising way for reconfigurable non-Hermitian photonic devices, which may find applications in tunable on-chip sensors, isolators and so on.

Anomalous wavefront control of third-harmonic generation via graphene-based nonlinear metasurfaces in the terahertz regime.

Freely controlling wavefronts with metasurfaces has been widely studied in linear optical systems. By constructing phase gradient meta-atoms with nonlinear responses, the wavefronts of high-harmonic fields in nonlinear metasurfaces can be arbitrarily steered by following nonlinear generalized Snell's law (NGSL). However, for incident angles above the critical angle, NGSL fails to predict the generated nonlinear waves. In this work, by involving the reciprocal lattice effect of the nonlinear metasurface, we show a modified diffraction law to completely describe the nonlinear diffraction phenomena. This law is numerically demonstrated and confirmed by designed graphene-based nonlinear metasurfaces in the terahertz regime. Moreover, based on the diffraction law, we designed a nonlinear retroreflector and realized tunable control over a nonlinear wavefront in a single nonlinear metasurface. Our work provides a way to manipulate nonlinear waves and provides a better design of functional nonlinear metadevices.