A wide star-black-hole binary system from radial-velocity measurements.

All stellar-mass black holes have hitherto been identified by X-rays emitted from gas that is accreting onto the black hole from a companion star. These systems are all binaries with a black-hole mass that is less than 30 times that of the Sun1-4. Theory predicts, however, that X-ray-emitting systems form a minority of the total population of star-black-hole binaries5,6. When the black hole is not accreting gas, it can be found through radial-velocity measurements of the motion of the companion star. Here we report radial-velocity measurements taken over two years of the Galactic B-type star, LB-1. We find that the motion of the B star and an accompanying Hα emission line require the presence of a dark companion with a mass of [Formula: see text] solar masses, which can only be a black hole. The long orbital period of 78.9 days shows that this is a wide binary system. Gravitational-wave experiments have detected black holes of similar mass, but the formation of such massive ones in a high-metallicity environment would be extremely challenging within current stellar evolution theories.

Phenanthrene-Incorporated Isoamethyrin: A Near-Planar Macrocycle That Display Enhanced Aromaticity via Protonation-Triggered Conformation Changes.

Controlling the aromaticity in expanded porphyrins is a forefront research topic, and the strategy of using protonation-triggered conformational changes to fine-tune electronic properties and aromaticity has yet to be generalized in rigid and planar expanded porphyrins. Here, we synthesized phenanthrene-incorporated isoamethyrins that possess near-planar conformations and nonaromatic characters. However, when methanesulfonic acid (MSA) was added, geometric deformations occurred to minimize the unfavorable strain, resulting in macrocycles that were weakly aromatic as a whole.

Ropivacaine with Dexmedetomidine or Dexamethasone in a Thoracic Paravertebral Nerve Block Combined with an Erector Spinae Plane Block for Thoracoscopic Lobectomy Analgesia: A Randomized Controlled Trial.

Objective: This study aimed to investigate the effect of ropivacaine with dexmedetomidine or dexamethasone in a thoracic paravertebral nerve block (TPVB) combined with an erector spinae plane block (ESPB) for thoracoscopic lobectomy analgesia. Methods: A total of 97 patients undergoing thoracoscopic lobectomy under general anesthesia were enrolled in this study and randomly divided into three groups, ie, a ropivacaine group (Group R), a ropivacaine + dexmedetomidine group (Group R1), and a ropivacaine + dexamethasone group (Group R2). Ultrasound-guided TPVB combined with an erector spinae plane block was given after anesthesia induction. The following were applied to each group: Group R received 30 mL of 0.5% ropivacaine + 5 mL of a normal saline mixture; Group R1 received 30 mL of 0.5% ropivacaine + 5 mL of a 1 µg/kg dexmedetomidine mixture; Group R2 received 30 mL of 0.5% ropivacaine + 5 mL of an 8 mg dexamethasone mixture. The primary observation index was the time to the first postoperative remedial analgesia. The secondary observation indexes were the intraoperative consumption of propofol and sufentanil, time to waking from anesthesia, time to extubation, postoperative numerical rating scaltpe (NRS) score, postoperative sufentanil consumption, remedial analgesic dosage, and adverse reactions. Results: When compared with Group R, the time to first postoperative remedial analgesia was longer, the intraoperative and postoperative sufentanil consumption and flurbiprofen axetil remedial analgesic dose were lower, and the time to waking from anesthesia and time to extubation were shorter in groups R1 and R2 (P < 0.05). The NRS scores at 1, 6, 12, and 24 h postoperatively in groups R1 and R2 were lower than in Group R at the same time points (P < 0.05). Conclusion: Ropivacaine with dexmedetomidine or dexamethasone in TPVB combined with ESPB could prolong the time to first postoperative remedial analgesia, reduce perioperative sufentanil and postoperative remedial analgesic drug consumption, and decrease the postoperative NRS score in patients undergoing thoracoscopic lobectomy.

Rapid diagnosis of papillary thyroid carcinoma with machine learning and probe electrospray ionization mass spectrometry.

Frozen section examination could provide pathological diagnosis for surgery of thyroid nodules, which is time-consuming, skill- and experience-dependent. This study developed a rapid classification method for thyroid nodules and machine learning. Total 69 tissues were collected including 43 nodules and 26 nodule-adjacent tissues. Intraoperative frozen section was first performed to give accurate diagnosis, and the rest frozen specimen were pretreated for probe electrospray ionization mass measurement. By multivariate analysis of mass scan data, a series compounds were found downregulated in the extraction solution of papillary thyroid carcinoma (PTC), but some were found upregulated by mass spectrometry imaging. m/z 758.5713 ([PC[34:2] + H]+ ), m/z 772.5845 ([PC[32:0] + K]+ ), and m/z 786.6037 ([PC[36:2] + H]+ ) were firstly identified as potential biomarkers for nodular goiter (NG). Machine learning was employed by means of support vector machine (SVM) and random forest (RF) algorithms. For classification of PTC from NG, SVM and RF algorithms exhibited the same performance and the concordance was 94.2% and 94.4% between prediction and pathological diagnosis with positive and negative mass dataset, respectively. For the classification of PTC from PTC adjacent tissues, SVM was better than RF and the concordance was 93.8% and 83.3% with positive and negative mass dataset, respectively. With the identified compounds as training features, the sensitivity and specificity are 87.5% and 88.9% for the test set. The developed method could also correctly predict the malignancy of one medullary thyroid carcinoma and one adenomatous goiter (benign). The diagnosis time is about 10 min for one specimen, and it is very promising for the intraoperative diagnosis of papillary thyroid carcinoma.