Pseudospin-selective Floquet band engineering in black phosphorus.

Time-periodic light field has emerged as a control knob for manipulating quantum states in solid-state materials1-3, cold atoms4 and photonic systems5 through hybridization with photon-dressed Floquet states6 in the strong-coupling limit, dubbed Floquet engineering. Such interaction leads to tailored properties of quantum materials7-11, for example, modifications of the topological properties of Dirac materials12,13 and modulation of the optical response14-16. Despite extensive research interests over the past decade3,8,17-20, there is no experimental evidence of momentum-resolved Floquet band engineering of semiconductors, which is a crucial step to extend Floquet engineering to a wide range of solid-state materials. Here, on the basis of time and angle-resolved photoemission spectroscopy measurements, we report experimental signatures of Floquet band engineering in a model semiconductor, black phosphorus. On near-resonance pumping at a photon energy of 340-440 meV, a strong band renormalization is observed near the band edges. In particular, light-induced dynamical gap opening is resolved at the resonance points, which emerges simultaneously with the Floquet sidebands. Moreover, the band renormalization shows a strong selection rule favouring pump polarization along the armchair direction, suggesting pseudospin selectivity for the Floquetband engineering as enforced by the lattice symmetry. Our work demonstrates pseudospin-selective Floquet band engineering in black phosphorus and provides important guiding principles for Floquet engineering of semiconductors.

Evolution of the flat band and the role of lattice relaxations in twisted bilayer graphene.

Magic-angle twisted bilayer graphene exhibits correlated phenomena such as superconductivity and Mott insulating states related to the weakly dispersing flat band near the Fermi energy. Such a flat band is expected to be sensitive to both the moiré period and lattice relaxations. Thus, clarifying the evolution of the electronic structure with the twist angle is critical for understanding the physics of magic-angle twisted bilayer graphene. Here we combine nano-spot angle-resolved photoemission spectroscopy and atomic force microscopy to resolve the fine electronic structure of the flat band and remote bands, as well as their evolution with twist angle from 1.07° to 2.60°. Near the magic angle, the dispersion is characterized by a flat band near the Fermi energy with a strongly reduced band width. Moreover, we observe a spectral weight transfer between remote bands at higher binding energy, which allows to extract the modulated interlayer spacing near the magic angle. Our work provides direct spectroscopic information on flat band physics and highlights the important role of lattice relaxations.

Ultrafast Carrier Relaxation Dynamics in a Nodal-Line Semimetal PtSn4.

Topological Dirac nodal-line semimetals host topologically nontrivial electronic structure with nodal-line crossings around the Fermi level, which could affect the photocarrier dynamics and lead to novel relaxation mechanisms. Herein, by using time- and angle-resolved photoemission spectroscopy, we reveal the previously inaccessible linear dispersions of the bulk conduction bands above the Fermi level in a Dirac nodal-line semimetal PtSn4, as well as the momentum and temporal evolution of the gapless nodal lines. A surprisingly ultrafast relaxation dynamics within a few hundred femtoseconds is revealed for photoexcited carriers in the nodal line. Theoretical calculations suggest that such ultrafast carrier relaxation is attributed to the multichannel scatterings among the complex metallic bands of PtSn4 via electron-phonon coupling. In addition, a unique dynamic relaxation mechanism contributed by the highly anisotropic Dirac nodal-line electronic structure is also identified. Our work provides a comprehensive understanding of the ultrafast carrier dynamics in a Dirac nodal-line semimetal.

Computation-Guided Design of a Stimulus-Responsive Multienzyme Supramolecular Assembly.

The construction of stimulus-responsive supramolecular complexes of metabolic pathway enzymes, inspired by natural multienzyme assemblies (metabolons), provides an attractive avenue for efficient and spatiotemporally controllable one-pot biotransformations. We have constructed a phosphorylation- and optically responsive metabolon for the biodegradation of the environmental pollutant 1,2,3-trichloropropane.

Survival analyses of different treatment modalities and clinical stage for hypopharyngeal carcinoma.

Objective: We investigated the effects of different treatment modalities and clinical stage for hypopharyngeal carcinoma (HPC) patients. Methods: Between February 2004 and December 2012, 167 HPC patients were reviewed. We calculated overall survival (OS), progression-free survival (PFS), local failure-free survival (LFFS), regional failure-free survival (RFFS), and distant metastasis failure-free survival (DMFFS) using the Kaplan-Meier method and compared various survival outcomes between definitive chemoradiotherapy (CRT) and surgery-based therapy (SBT). Results: There were no significant differences in baseline characteristics between SBT (n = 102) and definitive CRT (n = 65) groups. The 5-year rates of OS (59.7% vs. 24.0%, p < 0.0001) and PFS (49.9% vs. 22.6%, p = 0.0002) were significantly better in patients who received SBT than in those who received definitive CRT. The SBT group also obtained better LFFS (p < 0.0001), RFFS (p = 0.0479), and DMFFS (p = 0.0110). We did similar analyses by different T-classification (T1-2, T3, and T4) and found that SBT had better OS (p < 0.0001 and p = 0.0020), PFS (p < 0.0001 and p = 0.0513), LFFS (p = 0.0002 and p = 0.0075), RFFS (p = 0.1949 and p = 0.0826), and DMFFS (p = 0.0248 and p = 0.0436) in the T4 and T1-2 subgroups but similar OS (p = 0.9598), PFS (p = 0.5052), RFFS (p = 0.9648), and DMFFS (p = 0.8239) in T3 patients. Analyses by different overall stages revealed no differences between definitive CRT and SBT for stage III patients but significantly better results for stage IV patients who received SBT. Conclusions: SBT can obtain significant survival benefits when compared with definitive CRT for the whole cohort of patients. Definitive CRT has similar survival outcomes compared with SBT only for T3 tumors or overall stage III disease.

Comparison the acute toxicity of two different induction chemotherapy schedules with cisplatin and fluorouracil in nasopharyngeal carcinoma patients.

PURPOSE: To compare the acute toxicity of two different induction chemotherapy (IndCT) regimen followed by the same IMRT in patients with advanced nasopharyngeal carcinoma (NPC). MATERIALS AND METHODS: From July 2015 to December 2016, 110 NPC patients with stage III-IV diseases were prospectively randomized to receive either a conventional triweekly cisplatin + 5-fluorouracil (PF) for 3 cycles or weekly P-F for 10 doses, followed by the same IMRT to both arms. The primary endpoints of this study were grade 3/4 and any grade acute toxicities during IndCT period. The secondary endpoints included tumor response and various survivals. RESULTS: Baseline patient characteristics were comparable in both groups. Patients who received weekly P-F experienced significant reduction of grade 3/4 acute toxicities, including neutropenia (12.7% vs. 40.0%, P = 0.0012), anorexia (0% vs. 14.6%, P = 0.0059), mucositis (0% vs. 14.6%, P = 0.0059), and hyponatremia (0% vs. 16.4%, P = 0.0027), compared with the triweekly PF group, resulting in fewer IndCT interruptions (1.8% vs. 16.4%, P = 0.0203), emergency room visits (0% vs. 12.7%, P = 0.0128), and additional hospitalizations (0% vs. 9.1%, P = 0.0568). The acute toxicities during IMRT period were similar. Weekly P-F arm had higher complete response rates (83.6% vs. 61.8%, P = 0.0152) and lower relapse rates (16.4% vs. 33.3%, P = 0.0402) after a median follow-up of 67 months. Kaplan-Meier survival analyses revealed a better trend of locoregional failure-free (P = 0.0892), distant metastasis failure-free (P = 0.0775), and progression-free (P = 0.0709) survivals, favoring the weekly P-F arm. CONCLUSION: IndCT of weekly schedule does reduce acute toxicities without compromised tumor response and survivals.

A newly designed femtosecond KBe2BO3F2 device with pulse duration down to 55 fs for time- and angle-resolved photoemission spectroscopy.

Developing a widely tunable vacuum ultraviolet (VUV) source with a sub-100 fs pulse duration is critical for ultrafast pump-probe techniques such as time- and angle-resolved photoemission spectroscopy (TrARPES). While a tunable probe source with a photon energy of 5.3-7.0 eV has been recently implemented for TrARPES by using a KBe2BO3F2 (KBBF) device, the time resolution of 280-320 fs is still not ideal, which is mainly limited by the duration of the VUV probe pulse generated by the KBBF device. Here, by designing a new KBBF device, which is specially optimized for fs applications, an optimum pulse duration of 55 fs is obtained after systematic diagnostics and optimization. More importantly, a high time resolution of 81-95 fs is achieved for TrARPES measurements covering the probe photon energy range of 5.3-7.0 eV, making it particularly useful for investigating the ultrafast dynamics of quantum materials. Our work extends the application of the KBBF device to ultrafast pump-probe techniques with the advantages of both a widely tunable VUV source and ultimate time resolution.

Maintenance metronomic chemotherapy for metastatic/recurrent nasopharyngeal carcinoma.

BACKGROUND: We investigated the survival impact and toxicity of maintenance metronomic chemotherapy in patients with metastatic/recurrent nasopharyngeal carcinoma (met/rec NPC). METHODS: Ninety-eight patients with met/rec NPC were first salvaged by IV cisplatin-based chemotherapy and showed nonprogression disease; then maintenance metronomic chemotherapy for at least 12 months was recommended. We analyzed the treatment outcome between patients who received (n = 51) and did not receive (n = 47) maintenance chemotherapy. RESULTS: Baseline patient characteristics showed no significant differences between both arms. Median overall survival for patients with and without maintenance chemotherapy was 36.0 and 12.3 months, respectively (p < 0.0001). Similarly, median progression-free survival was 24.7 and 7.3 months, respectively (p < 0.0001). Furthermore, toxicities during maintenance oral chemotherapy period were usually mild. Transient grade 3 leucopenia (9.8%), anemia (3.9%), thrombocytopenia (7.8%), and no grade 4 toxicity were observed. CONCLUSION: After IV salvage chemotherapy, maintenance oral metronomic chemotherapy significantly improved overall and progression-free survivals while demonstrating low toxicity in patients with met/rec NPC.

Survival impacts of different nodal characteristics and T-classification in N3 nasopharyngeal carcinoma patients.

OBJECTIVES: We investigated the survival impacts of various nodal characteristics and T-classification on nasopharyngeal carcinoma (NPC) patients with the 8th AJCC/UICC staging criteria N3. MATERIALS AND METHODS: Pretreatment MRIs from 110 staged N3 NPC patients were reviewed. There were 23 T1, 25 T2, 32 T3, and 30 T4, respectively. All except one patient belonged to WHO type II pathology. All patients received curative radiotherapy 68.0-76.8 Gy plus different chemotherapy, including induction, concurrent, adjuvant or any combination. Various endpoints, including OS (overall survival), DFS (disease-free survival), LRFFS (locoregional failure-free survival), DMFFS (distant metastasis failure-free survival) were compared between different nodal characteristics and T-classification. RESULTS: There were no statistically significant differences in all analyzed survival curves between various nodal characteristics, including unilateral N3 vs. bilateral N3, "large" nodes (>6 cm) alone vs. "low" nodes (below the caudal border of cricoid cartilage) alone vs. combined "large" and "low" nodes, risk score 1 vs. 2 vs. 3 vs. 4 (by counting the sum of "large" and "low" nodes in the same case), and radiologic extra-nodal extension. Patients with T4, compared with those of T1-3 have worse OS (5-year rates, 42.2% vs. 82.8%, P < 0.0001), DFS (5-year rates, 43.9% vs. 68.9%, P = 0.0037), LRFFS (5-year rates, 69.3% vs. 82.7%, P = 0.0432), and DMFFS (5-year rates, 57.2% vs. 77.7%, P = 0.0163). CONCLUSIONS: Our results support merging previous N3a and N3b as a N3 category in the 8th edition new staging system. Patients with T4N3 diseases have extremely poor outcome and deserve to strengthen the treatment intensity in future trials.

Effects of Epstein-Barr virus viral load and different treatment modality for stage III nasopharyngeal carcinoma.

BACKGROUND: We investigated treatment results, the effects of different treatment modality, and pretreatment Epstein-Barr virus (EBV) viral load for stage III nasopharyngeal carcinoma (NPC) patients. METHODS: The initial definitive treatment for 356 stage III NPC patients consisted of concurrent chemoradiotherapy (CCRT) or induction chemotherapy plus radiotherapy (IndCT-RT). The pretreatment EBV DNA level separated patients into a high (n = 106) or low (n = 250) viral load (≥ or < 1000 copies/mL) subgroup. Outcome measures include relapse rates and various survivals. RESULTS: The 5-year rates of overall survival (OS), progression-free survival (PFS), distant metastasis failure-free survival (DMFFS), and locoregional failure-free survival (LRFFS) were 88.6%, 83.0%, 90.5%, and 90.5%, respectively. Patient characteristics and pretreatment viral load between IndCT-RT and CCRT were no significant differences except for a higher percentage of N2 disease in the IndCT-RT subgroup. Both treatment modality resulted in similar relapse rates (P = .56), OS (P = .20), PFS (P = .53), DMFFS (P = .89), and LRFFS (P = .35). However, patients with a high viral load experienced a higher relapse rate (33.0% vs 12.4%, P < .001) and worse OS (5-year rate, 79.0% vs 92.8%, P < .001), PFS (73.7% vs 88.4%, P < .001), DMFFS (80.2% vs 95.0%, P < .001), and LRFFS (85.6% vs 92.6%, P = .005) than those with a low viral load. CONCLUSION: Long-term treatment results for stage III NPC patients are rather good. IndCT-RT can achieve the same treatment outcome as CCRT. Risk grouping by pretreatment viral load identified a subgroup (30%) of patients associated with a significantly higher relapse rates and worse survivals. These high-risk patients need to strengthen treatment intensity in future trials.

Comparison the clinical outcomes with altered versus conventional fractionated radiotherapy plus concurrent chemotherapy for advanced nasopharyngeal carcinoma.

BACKGROUND: The purpose of this study was to compare the long-term survivals between altered fractionated and conventional fractionated radiotherapy with the same concurrent chemoradiotherapy (concurrent CRT) for patients with advanced nasopharyngeal carcinoma (NPC). METHODS: We retrospectively reviewed 203 patients with NPC who received radiotherapy (RT) by either a conventional fractionated (70-74 Gy/35-37 fractions/7-8 weeks) or altered fractionated (72-75 Gy/45 fractions/6 weeks) schedule plus the same concurrent CRT. RESULTS: The patient characteristics between conventional fractionated and altered fractionated groups showed similar distribution. The 5-year rates of nasopharyngeal failure-free, neck failure-free, and distant metastasis failure-free survival between conventional fractionated and altered fractionated groups were 88% versus 86% (P = .7781), 95% versus 93% (P = .4176), and 76% versus 73% (P = .4029), respectively. The overall survival (OS; 5-year rates were 64% versus 62%; P = .4812) and progression-free survival (PFS; 5-year rates were 67% versus 63%; P = .3829) rates also showed no significant differences. The acute and late toxicities were similar between both groups. CONCLUSION: Altered fractionated and conventional fractionated RT achieved similar survival outcome when concurrent CRT strategy was used for advanced NPC.

Long-term clinical outcome in nasopharyngeal carcinoma patients with post-radiation persistently detectable plasma EBV DNA.

PURPOSE: To investigate the long-term clinical outcome of nasopharyngeal carcinoma (NPC) patients with persistently detectable plasma EBV (pEBV) DNA after curative radiotherapy (RT). RESULTS: The post-RT pEBV DNA levels were very lower copy number (median 21, interquartile range 8-206 copies/ml). After long-term follow-up, the relapse rate was 64.8%, the median time to progression 20 months, and 5-year overall survival (OS) 49.6%. Thirty-two of 39 (82.1%) patients with high viral load (≥ 100 copies/ ml) developed tumor relapse, whereas 57.0% (49/86) patients with low viral load (< 100 copies/ml) had tumor relapse (P = 0.0065). The 5-year OS rates were 20.5% and 62.9% for patients with viral load ≥ and < 100 copies/ml (median survival, 20 vs. 100 months; P < 0.0001). Patients who received adjuvant chemotherapy (AdjCT) experienced significant reduction in distant failures (66.2% vs. 31.6%; P = 0.0001) but similar locoregional recurrences (P = 0.2337). The 5-year OS rates were 69.4% for patients who received AdjCT compared with 33.2% for those of without AdjCT (median survival, 111 vs. 32 months; P < 0.0001). METHODS: We screened 931 newly diagnosed NPC patients who finished curative RT and found 125 patients (13.4%) with detectable pEBV DNA one week after RT. The clinical characteristics, treatment modality, subsequent failure patterns and survivals were analyzed. CONCLUSIONS: NPC patients with persistently detectable pEBV DNA after curative RT have a higher rate of treatment failure and poor survivals. Levels of the post-RT pEBV DNA and administration of AdjCT affect the final outcome significantly.

[Intractable facial paralysis treated with different acupuncture and acupoint embedding therapies: a randomized controlled trial].

OBJECTIVE: To compare the clinical therapeutic effects on intractable facial paralysis among acupuncture, acupoint catgut embedding and PDS embedding. METHODS: Two hundred and seventy-nine patients of intractable facial paralysis were randomized into an acupuncture group, a catgut embedding group and a PDS embedding group, 93 cases in each one. Cuanzhu (BL 2), Yuyao (EX-HN 4), Taiyang (EX-HN 5), Xuanlu (GB 5), Dicang (ST 4), Jiache (ST 6), Quanliao (SI 18), Qianzheng (Extra), Xiaguan (ST 7) and Fengchi (GB 20) on the affected side and bilateral Hegu (LI 4) and Zusanli (ST 36) were selected in the three groups. In the acupuncture group, acupuncture was applied to those acupoints, once every two days; 10 treatments made one session; the successive three sessions were required. In the catgut embedding group and the PDS embedding group, catgut and PDS were embedded separately, once every 10 days; 3 treatments made one session and the successive two sessions were required. The therapeutic cycle was 2 months in the three groups. The therapeutic results were analyzed statistically 2 months later. The scores of Sunnybrook facial nerve grading system and the facial nerve electroneurography (ENoG) were used for the efficacy assessment before and after treatment in the three groups. RESULTS: After treatment, the score of Sunnybrook facial nerve grading system was improved apparently after treatment as compared with that before treatment in any of the three groups (all P < 0.05). The score in either of the embedding groups was better than that in the acupuncture group (both P < 0.05). The difference was not significant between the catgut embedding group and the PDS embedding group (P > 0.05). After treatment, ENoG wave ampli tude values in the frontal muscle and orbicularisoris muscle on the affected side were improved as compared with those before treatment in the three groups (all P < 0.05). Those in the catgut embedding group and the PDS embedding group were better than those in the acupuncture group (all P < 0.05), and had no significant difference as compared with those on the healthy side (P > 0.05). In the acupuncture group, ENoG wave amplitudes on the affected side were lower than those on the healthy side (both P < 0.05). CONCLUSION: Acupuncture, catgut embedding and PDS embedding at acupoints all achieve the therapeutic effects on intractable facial paralysis. However, the acupoint embedding therapy presents more advantages on the recovery of facial nerve function. The efficacy is similar between the catgut embedding and the PDS embedding.

[Biography of the outstanding acupuncturist DU Xiao-shan].

Professor DU Xiao-shan 's academic thought and clinical experiences was introduced in this paper. He has noble medical ethics and is fair to the patients without distinction. He has great learning and rich practical experiences, and he specializes in all kinds of common diseases as well as many difficult and complicated cases. He never stops studying the ancients to make innovation and he creates the technique of the quick-puncture and slow-twist and DU's heat-reinforce method. He teaches to carry forward acupuncture and moxibustion and his achievements have become an important part of acupuncture and moxibustion science.

[Facial nerve function index evaluation on deviation of the mouth in intractable facial palsy treated with sticking needle and traction method on three points of the mouth].

OBJECTIVE: To probe into the effective acupuncture technique for deviation of the mouth in intractable facial palsy. METHODS: One hundred and one cases of intractable facial palsy were randomly divided into an observation group (48 cases) and a control group (53 cases). Cuanzhu (BL 2), Sibai (ST 2), Jiache (ST 6) and Qianzheng (Extra) on the affected side were punctured in two groups. Additionally, three acupoints of the mouth were supplemented, named Dicang (ST 4), Kouheliao (LI 19) and Jiachengjiang (Extra) were added, and the sticking needle and traction method was adopted on them in observation group. the routine needling technique was applied in control group. The treatment was given once a day and 10-day treatment made one session. The changes in facial nerve function index (FNFI) were observed in 2 sessions of treatment. RESULTS: After treatment, FNFI in two groups increased significantly (both P < 0.01), but the improvement in observation group was better than that in control group (P < 0.01). In observation group, the basic recovery rate of FNFI was 87.5% (42/48), which was higher than that (67.9%, 36/53) in control group (P < 0.05). CONCLUSION: The sticking needle and traction method o three points is the quite effective approach in the treatment of deviation of the mouth in intractable facial palsy.