CFD simulation of cannabidiol delivery through microneedle patches.

This study investigates the efficiency and influence of microneedle parameters, specifically Needle Point Angle (a) and Needle Height (h), on the diffusion of Cannabidiol (CBD) across varying skin depths. Utilizing the Latin Hypercube Sampling method, twelve distinct cases were analyzed. Observations reveal a consistent high concentration of CBD delivered via the microneedle patch, with a notable decrease in concentration as the depth increases, displaying a non-linear trend. Multivariate polynomial regression offers a quantitative relationship between the variables, with the third-order bivariate fitting providing the most accurate representation. Compared to other CBD delivery mechanisms, microneedle patches present enhanced CBD concentrations, circumventing challenges faced by other methods such as dosage inaccuracy, systemic absorption issues, and CBD degradation. The results highlight the potential of microneedle patches as a promising avenue for optimized transdermal drug delivery.

When Artificial Intelligence Voices Human Concerns: The Paradoxical Effects of AI Voice on Climate Risk Perception and Pro-Environmental Behavioral Intention.

Artificial intelligence (AI)-enabled text-to-speech transformation has been widely employed to deliver online information in various fields. However, few studies have investigated the effect of the AI voice in environmental risk communication, especially in the field of climate change, an issue that poses a severe threat to global public health. To address this gap, the current study examines how the AI voice impacts the persuasive outcome of climate-related information and the potential mechanism that underlies this process. Based on the social and affect heuristics of voice, we propose a serial mediation model to test the effect of climate-related information delivered by different voice types (AI voice vs. human voice) in eliciting risk perception and motivating pro-environmental behavioral intention. Through an online auditory experiment (N = 397), we found the following. First, the AI voice was as effective as the human voice in eliciting risk perception and motivating pro-environmental behavioral intention. Second, compared with human voice, the AI voice yielded a listener's lower level of perceived identity oneness with the speaker, which decreased risk perception and subsequently inhibited pro-environmental behavioral intention. Third, compared with human voice, the AI voice produced a higher level of auditory fear, which increased risk perception and thereby led to stronger pro-environmental behavioral intention. The paradoxical role of the AI voice and its wise use in environmental risk communication for promoting global public health are discussed.

Perceived Information Overload and Unverified Information Sharing on WeChat Amid the COVID-19 Pandemic: A Moderated Mediation Model of Anxiety and Perceived Herd.

Individuals' unverified information sharing on social media, namely, sharing information without verification, is a major cause of the widespread misinformation amid the COVID-19 pandemic. The association between perceived information overload and unverified information sharing has been well documented in the cognitive overload approach. However, little is known about the underlying mechanism of this process. This study aims to explore the mediating role of anxiety and the moderating role of perceived herd between perceived information overload and unverified information sharing on WeChat. Anxiety demonstrates people's emotional response to the pandemic, whereas perceived herd describes a willingness to share certain information if it has been shared by many. The results of an online survey in China (N = 525) showed that perceived information overload was positively associated with unverified information sharing. In addition, this relationship was partially mediated by anxiety. Moreover, perceived herd positively moderated the link between anxiety and unverified information sharing, such that the indirect effect of perceived information overload on unverified information sharing via anxiety was significant in conditions where the level of perceived herd was high, whereas the indirect effect was not significant in conditions where the level of perceived herd was low. The moderated mediation model extends the cognitive overload approach and indicates that unverified information sharing is not only an individual strategy to cope with information overload but also a herding behavior to manage anxiety. Practical implications for curbing people's tendencies toward unverified information sharing on social media are discussed.

Local anesthesia, epidural anesthesia and general anesthesia comparison in lumbar disc herniation: a network meta-analysis.

There were 3 major anesthesia methods for discectomy: local, epidural and general. A lot of studies has been established to compare these three methods in different aspects, however, the result is still controversial. We conducted this network meta-analysis to evaluate these methods. Electronic databases including PubMed, EMBASE, Cochrane Library, were searched to identify clinical trials that reported the effects of local anesthesia general anesthesia and epidural anesthesia in lumbar disc herniation. Three indicators were included for evaluation: post-operative VAS score, complication, operation duration. In total, 12 studies and 2287 patients were included for this study. For complication, epidural anesthesia shows significantly lower rate compare to general anesthesia (OR: 0.45, 95% CI [0.24, 0.45], P=0.015), but local anesthesia didn't show significant result, no significant heterogeneity was observed between designs. For VAS score, epidural anesthesia showed a better effect (MD: -1.61, 95%CI [-2.24, -0.98]) compare to general anesthesia, and local anesthesia has a similar effect (MD: -0.91, 95%CI [-1.54, -0.27]). However this result showed a very high heterogeneity (I2=95%). For operation duration, local anesthesia showed a significant lesser time compare to general anesthesia (MD: -46.31(minutes), 95%CI [-73.73, -19.19]) but epidural anesthesia didn't have one, this result also showed a very high heterogeneity (I2=98%). Epidural anesthesia showed lesser post- operative complication compare to general anesthesia in lumbar disc herniation surgery.

Revealing the source of Jupiter's x-ray auroral flares.

Jupiter's rapidly rotating, strong magnetic field provides a natural laboratory that is key to understanding the dynamics of high-energy plasmas. Spectacular auroral x-ray flares are diagnostic of the most energetic processes governing magnetospheres but seemingly unique to Jupiter. Since their discovery 40 years ago, the processes that produce Jupiter's x-ray flares have remained unknown. Here, we report simultaneous in situ satellite and space-based telescope observations that reveal the processes that produce Jupiter's x-ray flares, showing surprising similarities to terrestrial ion aurora. Planetary-scale electromagnetic waves are observed to modulate electromagnetic ion cyclotron waves, periodically causing heavy ions to precipitate and produce Jupiter's x-ray pulses. Our findings show that ion aurorae share common mechanisms across planetary systems, despite temporal, spatial, and energetic scales varying by orders of magnitude.

Oxidative stress induces downregulation of TP53INP2 and suppresses osteogenic differentiation of BMSCs during osteoporosis through the autophagy degradation pathway.

Oxidative stress plays an important role in the pathogenesis of osteoporosis and impaired bone formation. However, the mechanisms behind which oxidative stress represses bone formation remains unclear. TP53INP2, a target of the tumor suppressor p53, is ubiquitously expressed in various cell types including BMSCs and contributes to autophagosome formation by recruiting ubiquitinated substrates to autophagosomes for degradation. However, little is known about its function in BMSCs and its relation to osteoporosis. In this study, first, we verified that the expression of TP53INP2 was persistently decreased in BMSCs derived from osteoporosis patients and OVX mice, and that the antioxidant N-acetylcysteine could ameliorate this decreased TP53INP2 level in vitro. Second, we identified that the mRNA and protein levels of TP53INP2 decreased in BMSCs under H2O2 induced oxidative stress in a dose-dependent manner, with resultant co-location of LC3 and TP53INP2. Additionally, the autophagy-lysosome system was involved in the degradation process of TP53INP2 and applying autophagy inhibitors (Baf-A1) could significantly increase the TP53INP2 levels in murine and human BMSCs under oxidative stress. Third, gain- and loss-of-function assays revealed that knockdown of TP53INP2 inhibited osteogenic differentiation of BMSCs, while overexpression of TP53INP2 promoted osteogenic differentiation of BMSCs in vitro. Further analysis demonstrated that TP53INP2 promoted osteogenic differentiation of BMSCs by activating Wnt/ß-cantenin signaling. DKK1, an inhibitor of Wnt signaling, resulted in osteogenic defects of BMSCs that had over-expressed TP53INP2. Lithium, a Wnt/ß-catenin activator, improved the mineralization ability in TP53INP2-knockdown BMSCs. Moreover, restoring TP53INP2 levels recovered OVX-derived BMSCs osteogenic differentiation and attenuated bone loss in OVX mice. Taken together, our study indicated that oxidative stress-induced downregulation of TP53INP2 suppressed osteogenic differentiation of BMSCs during osteoporosis and was mediated by the autophagy degradation pathway. These findings may introduce a novel therapeutic target for osteoporosis.

Comparison of surgical outcomes of lumbar disc herniation using local anesthesia and epidural anesthesia: A meta-analysis.

We performed this meta-analysis to evaluate the effects of epidural anesthesia and local anesthesia on the surgical outcomes of lumbar disc herniation (DH).Electronic databases including PubMed, EMBASE, Cochrane Library, and the Chinese Academic Journal Full-text Database were searched to identify randomized controlled trials (RCTs) that reported on the effects of local anesthesia and epidural anesthesia in lumbar DH surgical management. Evaluation indicators included: onset time of anesthesia, patient satisfaction, and the rate of adverse effects. There were 6 RCTs with a total of 606 patients in this meta-analysis: 274 cases in the local anesthesia group and 332 in the epidural anesthesia group.This meta-analysis demonstrated that the epidural anesthesia group had a better analgesic effect, a lower adverse effect rate (mean difference [MD] = 0.21, 95% confidence interval [CI] [0.08, 0.54], P = .001) and a better satisfaction rate: (MD = 6.54, 95% CI [2.77, 15.45], P < .0001). The duration of anesthesia was not statistically significant.Epidural anesthesia is a better choice for lumbar DH surgery compared to local anesthesia.

Very-Low-Frequency transmitters bifurcate energetic electron belt in near-earth space.

Very-Low-Frequency (VLF) transmitters operate worldwide mostly at frequencies of 10-30 kilohertz for submarine communications. While it has been of intense scientific interest and practical importance to understand whether VLF transmitters can affect the natural environment of charged energetic particles, for decades there remained little direct observational evidence that revealed the effects of these VLF transmitters in geospace. Here we report a radially bifurcated electron belt formation at energies of tens of kiloelectron volts (keV) at altitudes of ~0.8-1.5 Earth radii on timescales over 10 days. Using Fokker-Planck diffusion simulations, we provide quantitative evidence that VLF transmitter emissions that leak from the Earth-ionosphere waveguide are primarily responsible for bifurcating the energetic electron belt, which typically exhibits a single-peak radial structure in near-Earth space. Since energetic electrons pose a potential danger to satellite operations, our findings demonstrate the feasibility of mitigation of natural particle radiation environment.

Use of a locking intramedullary nail for the treatment of initial varus proximal humeral fracture: a prospective pilot study.

OBJECTIVE: To evaluate the feasibility of locked intramedullary nailing, rather than locking plate fixation combined with fibular allograft augmentation, for initial varus proximal humeral fractures. METHODS: This prospective pilot study enrolled patients with initial varus proximal humeral fractures that were treated with a locking intramedullary nail. Radiography was performed to evaluate fracture healing. Data about the visual analogue scale (VAS) pain score, Constant Shoulder Score (CSS), Disabilities of the Arm, Shoulder and Hand (DASH) score, American Shoulder and Elbow Surgeons (ASES) score and shoulder range of motion (ROM) were recorded. RESULTS: Twenty patients, including eight with Neer two-part and 12 with three-part fractures, were followed-up, with a mean time of 12.3 months. All patients sustained fractures that healed without re-varus. During the last follow-up, the shoulder function of the patients had recovered well, with a mean VAS pain score of 1.4, a mean CSS of 83.1, a mean DASH score of 80.8, a mean ASES score of 84.0 and a satisfactory ROM. In one patient, the proximal locking screw came out and was removed via a second surgery. CONCLUSIONS: The use of a locking intramedullary nail alone for initial varus proximal humeral two-/three-part fractures was feasible. This treatment has advantages, such as preventing re-varus and causing milder surgical trauma, than that seen with a locking plate.

Design of Multifunctional Mesosphere-Ionosphere Sounding System and Preliminary Results.

This paper describes a novel sounding system for which the functions of the medium frequency (MF) radar and the ionosonde are integrated on the same hardware platform and antenna structure, namely the middle atmosphere-ionosphere (MAI) system. Unlike the common MF radar, MAI system adopts the pseudo-random (PRN) phase-coded modulation technology, which breaks the limitation of the traditional monopulse mode. Through the pulse compression, only a small peak power is needed to achieve the signal-to-noise ratio (SNR) requirement. The excellent anti-jamming performance is also very suitable for the ionospheric sounding. One transmitting and six receiving modes are adopted for the MF sounding. While neglecting the structure of the T/R switches, the coupling interference between the transmitter and the receiver may also be avoided. Moreover, by employing a miniaturized antenna array composed of progressive-wave antennas for the MF receiving and ionospheric sounding, the MAI system takes account of the requirements of the inversion algorithms of MF radar and the large bandwidth need for the ionospheric sounding concurrently. Such an antenna structure can also greatly simplify the system structure and minimize the difficulty of deployment. The experiments verified the availability of the system scheme and its engineering application significance. Through further analysis of the sounding data, the wind field of the mesosphere, the electron density of D layer and electron density profile from layers E to F were obtained at the identical location. The capability of MAI system can play an important role in studying the interaction and coupling mechanism between the mesosphere and ionosphere.

Contactless treatment for scoliosis by electromagnetically controlled shape-memory alloy rods: a preliminary study in rabbits.

PURPOSE: To evaluate the safety and efficacy of a system aiming to correct scoliosis called "electromagnetically controlled shape-memory alloy rods" (EC-SMAR) used in a rabbit model. METHODS: We heat-treated shape-memory alloy (SMA) rods to achieve a transition temperature between 34 and 47 °C and a C-shape austenite phase. We then developed a water-cooled generator capable of generating an alternating magnetic field (100 kHz) for induction heating. We next studied the efficacy of this system in vitro and determined some parameters prior to proceeding with animal experiments. We then employed a rabbit model, in which we fixed a straight rod along the spinous processes intraoperatively, and conducted induction heating postoperatively every 4 days for 1 month, while performing periodic X-ray assessments. RESULTS: Significant kyphotic deformations with Cobb angles of about 45° (p < 0.01) were created in five rabbits, and no complications occurred throughout the experiment. The rabbits are still very much alive and do not show any signs of discomfort. CONCLUSIONS: This is the first system that can modulate spinal deformation in a gradual, contactless, noninvasive manner through electromagnetic induction heating applied to SMA alloy rods. Although this study dealt with healthy spines, it provides promising evidence that this device also has the capacity to correct human kyphosis and even scoliosis in the future. These slides can be retrieved under Electronic Supplementary Material.

Origin of two-band chorus in the radiation belt of Earth.

Naturally occurring chorus emissions are a class of electromagnetic waves found in the space environments of the Earth and other magnetized planets. They play an essential role in accelerating high-energy electrons forming the hazardous radiation belt environment. Chorus typically occurs in two distinct frequency bands separated by a gap. The origin of this two-band structure remains a 50-year old question. Here we report, using NASA's Van Allen Probe measurements, that banded chorus waves are commonly accompanied by two separate anisotropic electron components. Using numerical simulations, we show that the initially excited single-band chorus waves alter the electron distribution immediately via Landau resonance, and suppress the electron anisotropy at medium energies. This naturally divides the electron anisotropy into a low and a high energy components which excite the upper-band and lower-band chorus waves, respectively. This mechanism may also apply to the generation of chorus waves in other magnetized planetary magnetospheres.

TGF-ß1 reduces the oxidative stress-induced autophagy and apoptosis in rat annulus fibrosus cells through the ERK signaling pathway.

BACKGROUND: The aim of this study is to explore the effects of TGF-ß1 on autophagy and apoptosis induced by exogenous hydrogen peroxide (H2O2) in annulus fibrosus (AF) cells and possible signal pathways involved in this process. METHODS: AF cells were isolated from rat lumbar discs and subjected to different concentrations of exogenous H2O2 (50, 100, 200 µmol/L) for different time periods (0.5, 1, 2, and 4 h). Cell viability was determined by CCK-8 assay, and the levels of autophagy and apoptosis were evaluated by Western blotting and caspase 3, 8, 9 activity assay. By administration with different concentrations of TGF-ß1 (5, 10, 20 ng/mL), the effects of TGF-ß1 on autophagy and apoptosis induced by H2O2 were observed, and the possible signaling pathways were also investigated by using various apoptosis inhibitors or an autophagy inhibitor Bafilomycin A (Baf A) in AF cells. RESULTS: H2O2 significantly impaired cell viability in a dose- and time-dependent manner. H2O2 also induced a sudden and the highest level of autophagy at 1 h, and gradually increased apoptosis through ERK pathway. The mitochondrial pathway was involved in H2O2-induced apoptosis in AF cells. TGF-ß1 reduced the expression of p-ERK and downregulated the expressions of Beclin-1, LC3 II/I, and mitochondrial-related apoptotic proteins (Bax/Bcl-2, caspase-9). Meanwhile, TGF-ß1 downregulated the level of intracellular H2O2 through upregulating the expression level of glutathione peroxidase-1 (GPx-1). CONCLUSIONS: TGF-ß1 reduced autophagy and apoptosis induced by exogenous H2O2 through downregulating the expression of ERK in AF cells. TGF-ß1 could downregulate the level of ERK and intracellular H2O2 by upregulating GPx-1.

A Novel Ionospheric Sounding Network Based on Complete Complementary Code and Its Application.

In this paper, complete complementary code (CCC) sequences are applied to a High Frequency (HF) ionospheric sounding network. Ionosondes distributed at multiple locations use the mutually orthogonal CCC sequences to conduct vertical soundings synchronously. At the same time, thanks to the omnidirectional antennas, every station can receive the oblique echoes transmitted from the others. Due to the orthogonality between the code sequences, both vertical and oblique ionograms can be simultaneously obtained and completely separated. Through this method, the sounding efficiency can be enhanced, and the inversion difficulty can be reduced. Further, by using the data assimilation method, vertical and oblique sounding results can be combined to obtain a wide range of regional ionospheric characteristics. To verify the performance of this kind of sounding network, validation experiments are implemented to demonstrate that vertical and oblique ionograms can be obtained independently at the same time and inverted separately and that the maps of foF2 parameters obtained by using the data assimilation method provide more details than single vertical or oblique sounding.

Production of primary metabolites in Microcystis aeruginosa in regulation of nitrogen limitation.

The aim of this work was to study the regulatory effect of nitrogen (N) deficiency on primary metabolites in Microcystis aeruginosa, and promote the utilization of the alga. Low-N and Non-N conditions, especially Non-N, reduced the cell growth and photosynthetic abilities compared to Normal-N, as N deficiency triggered the down-regulation of genes involving in the photosynthetic process. Non-N not changed lipid content, due to no up-regulation of genes that promoted lipid synthesis. Soluble protein content significantly decreased under Non-N, which may result from the declined expression of genes relating to amino acid and histidyl-transfer RNA synthesis. Soluble and insoluble carbohydrate content significantly increased under Non-N, as the expression variation of genes blocked sugar degradation and promoted lipopolysaccharide synthesis. Therefore, M. aeruginosa can be used as the feedstock to produce carbohydrates under N deficiency for bioethanol production, and the remainder lipids after carbohydrate extraction can be used to produce biodiesel.

Scattering of Ultra-relativistic Electrons in the Van Allen Radiation Belts Accounting for Hot Plasma Effects.

Electron flux in the Earth's outer radiation belt is highly variable due to a delicate balance between competing acceleration and loss processes. It has been long recognized that Electromagnetic Ion Cyclotron (EMIC) waves may play a crucial role in the loss of radiation belt electrons. Previous theoretical studies proposed that EMIC waves may account for the loss of the relativistic electron population. However, recent observations showed that while EMIC waves are responsible for the significant loss of ultra-relativistic electrons, the relativistic electron population is almost unaffected. In this study, we provide a theoretical explanation for this discrepancy between previous theoretical studies and recent observations. We demonstrate that EMIC waves mainly contribute to the loss of ultra-relativistic electrons. This study significantly improves the current understanding of the electron dynamics in the Earth's radiation belt and also can help us understand the radiation environments of the exoplanets and outer planets.

Newly designed anterolateral and posterolateral locking anatomic plates for lateral tibial plateau fractures: a finite element study.

BACKGROUND: Lateral column tibial plateau fracture fixation with a locking screw plate has higher mechanical stability than other fixation methods. The objectives of the present study were to introduce two newly designed locking anatomic plates for lateral tibial plateau fracture and to demonstrate their characteristics of the fixation complexes under the axial loads. METHODS: Three different 3D finite element models of the lateral tibial plateau fracture with the bone plates were created. Various axial forces (100, 500, 1000, and 1500 N) were applied to simulate the axial compressive load on an adult knee during daily life. The equivalent maps of displacement and stress were output, and relative displacement was calculated along the fracture lines. RESULTS: The displacement and stresses in the fixation complexes increased with the axial force. The equivalent displacement or stress map of each fixation under different axial forces showed similar distributing characteristics. The motion characteristics of the three models differed, and the max-shear stress of trabecula increased with the axial load. CONCLUSIONS: These two novel plates could fix lateral tibial plateau fractures involving anterolateral and posterolateral fragments. Motions after open reduction and stable internal fixation should be advised to decrease the risk of trabecular microfracture. The relative displacement of the posterolateral fragments is different when using anterolateral plate and posterolateral plate, which should be considered in choosing the implants for different posterolateral plateau fractures.

[Corrigendum] Adenovirus-mediated overexpression of BMP-9 inhibits human osteosarcoma cell growth and migration through downregulation of the PI3K/AKT pathway.

Following the publication of this article, an interested reader drew to our attention an anomaly associated with the presentation of the western blots in Fig. 4B and C. These contained the same GAPDH control data, even though Fig. 4B and C were intended to show the inhibition of osteosarcoma cell migration by a recombinant adenovirus (ad) expressing bone morphogenetic protein 9 (adBMP-9) in two different cell lines, MG-63 and HOS, respectively. After having re-examined our original data, we realize that the same GAPDH control bands were inadvertently selected for Fig. 4B and C. A corrected version of Fig. 4, containing alternative data obtained from the experiments performed in duplicate, is presented below. Western blot assay was performed to examine the effect of adBMP-9 on metalloproteinase­9 (MMP-9) expression, showing that the expression of MMP-9 protein was significantly inhibited in the adBMP-9 group compared with the ad-green fluorescent protein (GFP) and the control (CON) groups in the MG-63 and HOS cell lines. In addition, no marked differences were noted between the ad-GFP group and the CON group. The error made with the selection of the control data did not affect the results in this study. We sincerely apologize for this mistake, and thank the reader of our article who drew this matter to our attention. Furthermore, we regret any inconvenience this mistake has caused. [the original article was published in the International Journal of Oncology 41: 1809-1819, 2012; DOI: 10.3892/ijo.2012.1617].

The morphological features of different Schatzker types of tibial plateau fractures: a three-dimensional computed tomography study.

BACKGROUND: Tibial plateau fractures are of great challenge to treat with open reduction and internal fixation, because fractures vary from simple to complex, with little or extensive articular involvement. Hence, recognition and comprehension of the fracture features will help orthopedic surgeons understand the injury mechanism better and manage these fractures by planning optimal surgical procedures. This study aimed to evaluate the morphological characteristics of tibial plateau fractures based on the Schatzker classification. METHODS: A total of 186 patients with 188 tibial plateau fractures from 2010 to 2014 in our hospital were reviewed using a computed tomography scan and three-dimensional (3D) reconstruction. The main fracture line angles (FLA) of Schatzker types I, II, and IV were measured. For each fracture, depression depth was measured, and the depression zone was also located. Depression zones were overlapped to obtain a frequency diagram. RESULTS: Schatzker type I and II fractures had three subtypes: single anterolateral fracture, single posterolateral fracture, and complex fracture (the anterolateral and posterolateral parts). Schatzker type IV fractures were also divided into three subtypes: single posteromedial fracture, single anteromedial fracture, and the whole medial fracture. For various Schatzker types and subtypes of fracture, fracture depression clustered and occurred at different locations of the tibial plateau. A significant difference was observed in the depression depth among the different Schatzker types (P < 0.01, Kruskal-Wallis test), especially between Schatzker type III and other types (Nemenyi test). There was no difference in the depression depth among the subtypes of Schatzker type II, whereas the difference was significant between the two subtypes of Schatzker type IV. CONCLUSIONS: Schatzker type I, II, and IV fractures could be divided into three corresponding subtypes by FLA. Various Schatzker types of fractures differed in location and depth of depression. A proper operative approach should be made based on the morphological characteristics of individual types of tibial plateau fractures.

Hypoxia facilitates the survival of nucleus pulposus cells in serum deprivation by down-regulating excessive autophagy through restricting ROS generation.

Nucleus pulposus (NP) cells reside in a hypoxic environment in vivo, while the mechanisms of how NP cells maintain survival under hypoxia are not clear. Autophagy is an important physiological response to hypoxia and implicated in the survival regulation in most types of cells. This study was designed to investigate the role of autophagy in the survival of NP cells under hypoxia. We found that appropriate autophagy activity was beneficial to the survival of NP cells in serum deprivation, while excessive autophagy led to death of the NP cells. Hypoxia facilitated the survival of NP cells in serum deprivation by down-regulating excessive autophagy. Hypoxia down-regulated the autophagy activity of NP cells through restricting the production of reactive oxygen species (ROS) and inactivating the AMPK/mTOR signaling pathway, and possibly through a pathway involving HIF-1α. We believed that understanding the autophagy response of NP cells to hypoxia and its role in cell survival had important clinical significance in the prevention and treatment of degenerative discogenic diseases.